This first section has two verses:

Titus 2:1-2
1 But speak thou the things which become sound doctrine:
2 That the aged men be sober, grave, temperate, sound in faith, in charity [love], in patience.

THE CHRISTIAN CHARACTER - THE SENIOR MEN
You must speak what befits sound teaching. You must charge the senior men to be sober, serious, prudent, healthy in Christian faith and love and fortitude.

THIS whole chapter deals with what might be called the Christian character in action. It takes various groups of people by their age and status and lays down what they ought to be within the world. It begins with the senior men.

They must be sober [temperate, quiet, sedate, serious, subdued, showing self-control]. The word is ne¯phalios, and it literally means sober as opposed to given to overindulgence in wine. The point is that, when a man has reached years of seniority, he ought to have learned what are and what are not true pleasures. The senior men should have learned that the pleasures of self-indulgence cost far more than they are worth.

They must be serious [characterized by deep thought, earnest, sincere, not trifling]. The word is semnos, and it describes the behaviour which is serious in the right way. It does not describe the appearance and manner of a person who is a gloomy killjoy, but the conduct of someone aware of living in the light of eternity, and expecting before very long to leave human fellowship for fellowship with God.

They must be prudent [wise, sagacious, circumspect, sober, careful]. The word is so¯phro¯n, and it describes someone with the mind which has everything under control. Over the years, the senior men must have acquired that cleansing, saving strength of mind which has learned to govern every instinct and passion until each has its proper place and no more.

The three words taken together mean that the senior man must have learned what can only be called the gravity, the serious nature, of life. A certain amount of recklessness and of thoughtlessness may be excusable in youth, but the years should bring their wisdom. One of the most tragic sights in life is the individual who has learned nothing through all the years.

Further, there are three great qualities in which the senior men must be healthy.

They must be healthy in faith. If we live really close to Christ, the passing of the years and the experiences of life – far from taking our faith away – will make our faith even stronger. The years must teach us not to trust God less but to trust him more.

They must be healthy in love. It may well be that the greatest danger of age is that it should drift into severe criticism and fault-finding. Sometimes the years take kindly sympathy away. It is fatally possible to become so settled in our ways that unconsciously we come to resent all new ideas and ways of doing things. But the years ought to bring not increasing intolerance but increasing sympathy with the views and mistakes of others.

They must be healthy in fortitude. The years should toughen us just as steel is strengthened in the fire, so that we are able to bear more and more, and emerge more and more as conquerors of life’s troubles. ~Barclay commentary

Now to the other commentaries.  We will begin with the general and go to the specific.

We will begin with the Matthew Henry Main. The commentary covers verses 1-10. I am giving you the commentary here that covers verse 2.

1. To the aged men. By aged men some understand elders by office, including deacons, etc. But it is rather to be taken of the aged in point of years. Old disciples of Christ must conduct themselves in every thing agreeably to the Christian doctrine.

That the aged men be sober, not thinking that the decays of nature, which they feel in old age, will justify them in any inordinacy [exceeding reasonable limits] or intemperance [lack of moderation or due restraint], whereby they conceit to repair them; they must keep measure in things, both for health and for fitness, for counsel and example to the younger.

Grave: levity [lack of appropriate seriousness or earnestness] is unbecoming in any, but especially in the aged; they should be composed and stayed [continue to be as specified], grave in habit, speech, and behaviour; gaudiness [brilliantly or excessively showy] in dress, levity and vanity in the behaviour, how unbeseeming [fit for, worthy, suitable] in their years!

Temperate, moderate and prudent [wise, sagacious, circumspect], one who governs well his passions and affections, so as not to be hurried away by them to any thing that is evil or indecent.

Sound in the faith, sincere and stedfast, constantly adhering to the truth of the gospel, not fond of novelties, nor ready to run into corrupt opinions or parties, nor to be taken with Jewish fables or traditions, or the dotages [senility] of their rabbin [rabbi]. Those who are full of years should be full of grace and goodness, the inner man renewing more and more as the outer decays.

In charity, or love; this is fitly joined with faith, which works by, and must be seen in, love, love to God and men, and soundness therein. It must be sincere love, without dissimulation [hypocrisy]: love of God for himself, and of men for God's sake. The duties of the second table [love of men] must be done in virtue of those of the first [love of God]; love to men as men, and to the saints as the excellent of the earth, in whom must be special delight; and love at all times, in adversity as well as prosperity. Thus must there be soundness in charity or love.

And in patience. Aged persons are apt to be peevish [cross, fretful obstinate], fretful [irritable], and passionate; and therefore need to be on their guard against such infirmities [lack of strength] and temptations. Faith, love, and patience, are three main Christian graces [1 Corinthians 13:13], and soundness [without defect] in these is much of gospel perfection. There is enduring patience and waiting [holding oneself in readiness] patience, both of which must be looked after; to bear evils becomingly, and contentedly to want the good till we are fit for it and it for us, being followers of those who through faith and patience inherit the promises. Thus as to the aged men. ~Matthew Henry Main

Now to the Matthew Henry Concise.  This commentary covers verses 1-10.

Old disciples of Christ must behave in every thing agreeably to the Christian doctrine. That the aged men be sober; not thinking that the decays of nature will justify any excess; but seeking comfort from nearer communion with God, not from any undue indulgence. Faith works by, and must be seen in love, of God for himself, and of men for God's sake. Aged persons are apt to be peevish and fretful; therefore need to be on their guard. Though there is not express Scripture for every word, or look, yet there are general rules, according to which all must be ordered. Young women must be sober and discreet; for many expose themselves to fatal temptations by what at first might be only want of discretion. The reason is added, that the word of God may not be blasphemed. Failures in duties greatly reproach Christianity. Young men are apt to be eager and thoughtless, therefore must be earnestly called upon to be sober-minded: there are more young people ruined by pride than by any other sin. Every godly man's endeavour must be to stop the mouths of adversaries. Let thine own conscience answer for thine uprightness. What a glory is it for a Christian, when that mouth which would fain open itself against him, cannot find any evil in him to speak of! ~Matthew Henry Concise.

Now some items from the Biblical Illustrator:

That the aged men be sober
The temptations and duties of old men

I. Sins to be avoided.
1. Indulgence in wine.
2. Irreverence.
3. Folly, “Temperate” here is really prudent, sound minded.

II. Virtues to be cherished.
1. Stability.
2. Love.
3. Patience ~Biblical Illustrator

Behaviour suitable for the aged
He that hath received much must bring forth much fruit, as the servant that had five talents committed unto him gained five other talents. So old men must be grave and sober, and carry a majesty in their countenance, that they may after a sort resemble the majesty of God.

As gravity and sobriety agreeth to every age, so most especially to the elder age, contrary to which is lightness, lasciviousness, and waywardness, which make them not honourable, but odious, not to be reverenced, but to be despised in the eyes of the younger sort.

Let them adorn their years with those virtues which the apostle nameth. If they be careful to express these things which become wholesome doctrine, they shall manifestly show that their living so in the world hath not been in vain; but honour is not seemly for a fool.

The wise man saith, “The beauty of the young men is their strength, and the glory of the aged is the greyheaded,” that is, wisdom, counsel, experience, whereby they are more adorned than the young man is beautified by his bodily strength. For the ornaments of the mind are to be preferred before the properties of the body.

Again, they must be examples of a godly life and holy conversation, that youth may stand in fear to commit any indecent and unseemly thing in their presence. Thus Job saith of himself (chap 29), “When I went out of the gate, the young men saw me, and hid themselves.”

But when the elder sort are ringleaders and examples of an evil and corrupt life, there is more gravity on their heads than piety in their hearts; in their white hairs than in their behaviour; and so the crown of honour is taken from them, and they are justly condemned, despised, and reproached of those of whom they should be honoured.

For we may see old men so hardened in wickedness, that if a man would find whole heaps of wickedness, he need seek no farther but to them. We are all to honour the grey head and to magnify old age, for (as Solomon saith) “Age is a crown of glory when it is found in the way of righteousness,” whereby he meaneth that old age, seasoned with a godly life and upright, bringeth with it as great glory as a crown on the head and a sceptre in the hand doth unto a king, and therefore such old men are greatly to be reverenced and highly to be esteemed.

But many, except they should be honoured for their ignorance, superstition, frowardness, maliciousness, waywardness, covetousness, drunkenness, licentiousness, and self-will, there is nothing else to be found in them, to be learned of them, to be gathered from them. By these foul enormities they bring themselves into contempt, and bring shame and reproach upon their own heads, so that no man defameth and dishonoureth them so much as themselves. Surely, if young men misbehave and misgovern themselves, they are not to be excused, but to be reproved, because they ought to order their lives aright, and remember their Creator in the days of their youth, and not deserve to be evil spoken or reported of; but old folks are doubly worthy of the shame that men do them, if they be not honoured for their virtues. They should learn by their long life and old age to grow in the knowledge of God and His Son Jesus Christ, to hate sin, to delight in righteousness, and daily to die unto the world. ~Biblical Illustrator

Now to the specific commentaries. The various commentaries breakout this verse in different ways, so I will use this one:

1] That the aged men.
2] Be sober.
3] Grave.
4] Temperate.
5] Sound in faith, in charity [love], in patience.

1] That the aged men.
That the aged men - All aged men - for there is no reason to suppose that the apostle refers particularly to those who were in office, or who were technically elders, or Presbyters. If he had, he would have used the common word - πρεσβύτερος presbuteros - “presbyter” instead of the unusual word - πρεσβύτης presbutēs - an old or aged man - a word which occurs nowhere else in the New Testament except in Luke 1:18, “For I am an old man,” and Philemon 1:9, “being such an one as Paul the aged.” It is in no instance applied to an office. Besides, the instructions which Titus was to give to such men was not that which especially pertained to elders as officers in the church, but to all old men. The idea is, that he was to adapt his instructions to the special character of different classes of his hearers. The aged needed special instructions, and so did the young. ~Barnes Notes

That the aged men be sober - It is very likely that the word aged is to be taken here in its literal sense; that it refers to advanced years, and not to any office in the Church: the whole context seems to require this sense.

For an old man to be a drunkard, a light and trifling person, and a glutton, and not to be sober, grave, and temperate, is not only blamable but monstrous. ~Adam Clarke

2] Be sober.
Be sober - Margin, “vigilant.” See the word explained in the notes at 1 Timothy 3:2, where it is rendered vigilant. In 1 Timothy 3:11, the same word is rendered sober. - Barnes Notes

Quoted verses:
1 Timothy 3:2 [see Lesson]
A bishop then must be blameless, the husband of one wife, vigilant, sober, of good behaviour, given to hospitality, apt to teach;

1 Timothy 3:11 [see Lesson]
Even so must their wives be grave, not slanderers, sober, faithful in all things.

That the aged men be sober - Or "vigilant", and watchful over themselves, their conduct and conversation, lest being evil, it should be drawn into an example by younger persons: this is to be understood not of men in office, of presbyters or elders; for their characters are described in the preceding chapter; but of men in years, of ancient men, that are professors of religion, and members of churches: who should also be... ~John Gill

3] Grave.
Grave - Serious; see the notes at 1 Timothy 3:8; compare the notes at Philippians 4:8, where the same word is rendered hottest. ~Barnes Notes

Quoted verses:
1 Timothy 3:8 [see Lesson]
Likewise must the deacons be grave, not doubletongued, not given to much wine, not greedy of filthy lucre;

Philippians 4:8
Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue, and if there be any praise, think on these things.

Grave - in their behaviour, speech, and dress; levity of conversation, frothy language, and airy dress, are very unbecoming aged persons: and who ought to be... ~John Gill

4] Temperate.
Temperate - σώφρονας sōphronas. Rather, prudent, or sober-minded. See it explained in the notes, 1 Timothy 3:2, where it is rendered “sober.” Also Titus 1:8. ~Barnes Notes

Quoted verses:
1 Timothy 3:2 ...mentioned above [see Lesson]
A bishop then must be blameless, the husband of one wife, vigilant, sober, of good behaviour, given to hospitality, apt to teach;

Titus 1:8 [see Lesson]
But a lover of hospitality, a lover of good men, sober, just, holy, temperate;

Temperate - in eating and drinking, especially the latter, to which old age is most addicted, and care should be taken that they be not over charged with it, and that day overtake them unawares, since they are upon the brink and borders of eternity: the word is rendered "discreet" in Titus 2:5 and sober in 1 Timothy 3:2 and both are characters suitable to men in years. ~John Gill

Quoted verses:
Titus 2:5 [see Lesson]
To be discreet, chaste, keepers at home, good, obedient to their own husbands, that the word of God be not blasphemed.

1 Timothy 3:2 ...mentioned above [see Lesson]
A bishop then must be blameless, the husband of one wife, vigilant, sober, of good behaviour, given to hospitality, apt to teach;

5] Sound in faith, in charity [love], in patience.

Sound in faith - 1 Timothy 1:10 note; Titus 1:13 note.
 

Quoted verses: 1 Timothy 1:10 [see Lesson] For whoremongers, for them that defile themselves with mankind, for menstealers, for liars, for perjured persons, and if there be any other thing that is contrary to sound doctrine; Here is the commentary: And if there be any other thing that is contrary to sound doctrine - To sound or correct teaching - for so the word doctrine means. The meaning is, if there is anything else that is opposed to the instruction which the law of God gives. ~Barnes Notes Titus 1:13 [see Lesson] This witness is true. Wherefore rebuke them sharply, that they may be sound in the faith; Here is the commentary: That they may be sound in the faith - That they may not allow the prevailing vices to corrupt their views of religion. ~Barnes Notes

Here is more Barnes Notes commentary:

In charity - In love; The meaning is, that an old man should evince love for all, especially for those who are good. He should have overcome, at his time of life, all the fiery, impetuous, envious, wrathful passions of his early years, and his mind should be subdued into sweet benevolence to all mankind. ~Barnes Notes

In patience - In the infirmities of old age - in the trials resulting from the loss of the friends of their early years - in their loneliness in the world, they should show that the effect of all God’s dealings with them has been to produce patience. The aged should submit to the trials of their advanced years, also, with resignation - for they will soon be over. A few more sighs, and they will sigh no more; a little longer bearing up under their infirmities, and they will renew their youth before the throne of God. ~Barnes Notes

Sound in faith, in charity, in patience - though they may be unhealthful in their bodies, and become decrepit through age, they should be sound in their minds; in the doctrine of faith, lest they should lead others into error; and their faith in Christ should appear to be right and genuine; and their love to God, to Christ, and to his people, should be real and sincere, and be taken off from the things of the world, of time and sense; an affection for which is an evil that frequently cleaves to old age: and patience should have its perfect work; not only to bear the infirmities of body, brought on by age; but whatsoever sufferings they may be called unto for the sake of Christ and his Gospel, in their last day; and to run out the race that is set before them. ~John Gill

So the message and admonition to old men is:

1] They should learn by their long life and old age to grow in the knowledge of God and His Son Jesus Christ, to hate sin, to delight in righteousness, and daily to die unto the world.

2] Be sober and vigilant. Be watchful over themselves, their conduct and conversation.

3] Be serious in your behavior, speech, dress and conversation.

4] Be temperate, moderate, wise and circumspect. One who governs well his passions and affections.

5] Sound in the faith. Be sincere and stedfast, constantly adhering to the truth of the gospel. Invoke love for all. Let patience have its perfect work.

These are the lessons of verse 2.