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.

We will begin with the Barclay commentary.

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 1.

Here is the third thing in the matter of the epistle. In the chapter foregoing, the apostle had directed Titus about matters of government, and to set in order the things that were wanting in the churches. Now here he exhorts him,

I. Generally, to a faithful discharge of his own office. His ordaining others to preach would not excuse himself from preaching, nor might he take care of ministers and elders only, but he must instruct private Christians also in their duty. The adversative particle (but) here points back to the corrupt teachers, who vented fables, things vain and unprofitable: in opposition to them, says he, “But speak thou the things that become sound doctrine, what is agreeable to the word, which is pure and uncorrupt, healthful and nourishing to eternal life.” Observe,

(1.) The true doctrines of the gospel are sound doctrines, formally and effectively; they are in themselves good and holy, and make the believers so; they make them fit for, and vigorous in, the service of God.

(2.) Ministers must be careful to teach only such truths. If the common talk of Christians must be uncorrupt, to the use of edifying, such as may minister grace to the hearers (Ephesians 4:29), much more must ministers' preaching be such. Thus the apostle exhorts Titus generally: and then,

Quoted verse:
Ephesians 4:29
Let no corrupt communication proceed out of your mouth, but that which is good to the use of edifying, that it may minister grace unto the hearers.

II. Specially and particularly, he instructs him to apply this sound doctrine to several sorts of persons, from Titus 2:2-10. Ministers must not stay in generals, but must divide to every one his portion, what belongs to his age, or place, or condition of life; they must be particular as well as practical in their preaching; they must teach men their duty, and must teach all and each his duty. Here is an excellent Christian directory, accommodated to the old and to the young; to men and women; to the preacher himself and to servants. ~Matthew Henry Main

Now to the Matthew Henry Concise.

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:

But speak thou the things which become sound doctrine
Connection with previous chapter: on the true pastor in contrast with the false

Titus’ duty is laid down by way of opposition, and knit to the former matter and chapter by the conjunction, But teach thou.

As if he had said, Although the false teachers whom I have described dote upon dreams, and feed their hearers with fancies and doctrines of men, to the corrupting and poisoning of souls, and turning men away from the truth, thou must be utterly unlike them in thy preaching; they speak pleasing things, but thou must speak profitable; they, by despising the simplicity of the gospel, fall not only into dangerous errors which they broach, but into loose and idle discourses which bring diseases upon the soul; but thou, on the contrary, must plainly and familiarly discover unto all estates of men and women their estates and duties, that thereby they may be brought to soundness; they cannot but speak and teach as they are; but let them trifle as they will, and live as they list, thou hast betaken thee to another service than that of man, and must carry thy ministry as becometh a sound teacher of the truth, which is according to godliness. ~Biblical Illustrator

Lessons for ministers
I. No Christian minister nor man must be so shaken at the ungodly courses of others in their rank as that they either give over or give back from their uprightness in their duties, for Titus, although he might seem to be cried down by the general voice of false and pompous teachers, yet must he not be silent; and though he might be troubled and opposed, yet must he not be timorous or sluggish; and though his doctrine was not received nor obeyed, yet he must not be weary of tendering and teaching it; yea, be it that the world would rather applaud mockers and time servers, yet must not he discontentedly with Jonas turn another way, but look unto his own duty in serving God, his Church, and men’s salvations. Let others stand or fall to their own masters, it is safe for every man so to lay his counters as that his Master may find him doing, yea, well-doing.

II. The scope of every minister in his teaching must be to feed the people of God with wholesome doctrine, such as may bring the souls of men to health and soundness. For

1. If the common talk of Christians must be edifying, ministering grace, bring sweetness to the soul, and health to the bones; if it be required of every righteous man that his lips should feed many, nay, more, if the law of grace must sit under the lips of every virtuous woman, much more must the minister’s, whose office in peculiar bindeth him to be a pastor or feeder, and that according to God’s own heart, he having for this purpose received his calling, gifts, and approbation of God.

2. Otherwise he perverteth the whole course of his life and calling, and is no better than those false apostles who, turning themselves from sound teaching to unfruitful discourses, called vain jangling, are said to rove and err from the right aim, like unskilful darters or shooters. ~Biblical Illustrator

Lessons for hearers
Hearers are hence taught sundry duties. As
1. To desire only this wholesome food that their souls may be well liking, laying aside their itching ears, which hunt after novelties, for the ministry is not appointed to beat the ear as music, but to sink into the soul as the food and medicine of it, by becoming the means and rule of life. Athenian hearing is the cause of Athenian preaching, and the diseases running upon such hearers showeth the curse of God on them, who with contempt of the manna from heaven, with the onions, garlic, and flesh of Egypt; these things they have upon their desire, and with them more than they desire, for they rot even between their teeth.

2. To receive the wholesome doctrine, as for the body we receive wholesome food what soever it be, or from whomsoever; let it be bitter sometimes, or seem too salt, yet if it be wholesome hunger findeth it savoury; no man but will strive to receive a bitter potion to restore his body out of any weakness to soundness; and yet who is it that will suffer a wholesome reproof to the recovery of soundness to the soul? and others stand so much upon toothsomeness of their meat, and must know their cooks so well, that before they can be resolved in these two, the plausibleness of the doctrine and the friendliness of the person, their souls are well nigh starved to death. Hence is it that we hear so many complaints. Oh, saith one, be seeketh not the goodwill of his hearers, nor casteth to please them; he is of a tart and bitter spirit; he seeketh to wound and gall, but he healeth nor suppleth not. But what preacheth he, whether any errors or the pure doctrine of God? No, say they, we cannot except against his doctrine. True, for they never trouble themselves so far as to examine it by the Word or themselves by it. But then, say I, is it the Word of God thou hearest, and the truth by thine own confession? Why dost thou then not tremble at that Word?

3. Hearers must hold wholesome doctrine when they have received it (2 Timothy 3:14). Continue in the things thou hast received; buy the truth, but sell it not, and bind it fast upon their hearts. And good reason, for if the meat be never so wholesome, if the stomach of the soul keep it not, but it slip the memory, and is not by meditation digested, the soul is as surely diseased as is the body when no sustenance will stay to strengthen it.

Quoted verse:
2 Timothy 3:14 [see Lesson]
But continue thou in the things which thou hast learned and hast been assured of, knowing of whom thou hast learned them;

4. Hearers must so desire, receive, and hold this wholesome food, as they may grow by it, showing by their thriving in grace that they have wholesome meat (Psalm 109:4), for as in the body, if meat, when it is digested, send not virtue whereby the operation of it appeareth in all the parts, the body is diseased, some obstruction or opilation hindereth the work of it, so is the soul obstructed with the itching ear, covetous thoughts, hardness of heart, formal worship, all which keep the soul barren and empty of grace, yea, lean and ill-looking in the eyes of God. Seeing, therefore, the Lord hath spread His table for us, and liberally furnished it with store of this wholesome food, let it appear in our souls, by our strength to labour in Christian duties to which we are called, to overcome the temptations unto sin, to carry our victory in our strife against our own lusts. ~Biblical Illustrator

Quoted verse:
Psalm 109:4
For my love they are my adversaries: but I give myself unto prayer.

Now to the specific commentaries.

This verse is not broken into any parts. Let us look at what the commentaries have to say.

But speak thou - In thine own ministry. In the previous chapter he had given him instructions as to the kind of persons who were to be put into the sacred office. Here he gives him special instructions in regard to his own preaching. “The things which become sound doctrine.” To wit, those which he proceeds immediately to specify. On the phrase sound doctrine, see the notes at 1 Timothy 1:10; compare 2 Timothy 4:3. ~Barnes Notes
 

Quoted verse: 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; From the commentary on this verse: 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 2 Timothy 4:3 [see Lesson] For the time will come when they will not endure sound doctrine; but after their own lusts shall they heap to themselves teachers, having itching ears; From the commentary on this verse: When they will not endure sound doctrine - Greek, “healthful doctrine;” i. e., doctrine contributing to the health of the soul, or to salvation. At that time they would seek a kind of instruction more conformable to their wishes and feelings. ~Barnes Notes

Now continuing in the specific commentaries.

But speak thou the things - This is a conclusion drawn from the preceding chapter: the Judaizing teachers not only taught a false doctrine, but they led an unholy life; Titus was to act directly opposite; he must teach a sacred doctrine, and the things which become it; he must proclaim the truth, and illustrate that truth. The people must not only be well instructed, but they must be holy in their lives. Principle and practice must go hand in hand. ~Adam Clarke

Next is the John Gill commentary:

But speak thou the things which become sound doctrine. - Concerning sound doctrine, and the form of it; see Gill on 2 Timothy 1:13. The things which become it are a good life and conversation, the various duties incumbent on professors of religion, according to their different station, age, and sex, which are observed in some following verses; these become the Gospel of Christ, and are ornamental to the doctrine of God our Saviour; and these are to be spoken of by the ministers of Christ, in their proper places, and at proper times; who ought not to be dumb, and keep silence at any time, but especially when there are many unruly and vain talkers: sound doctrine ought to be spoken out openly and publicly, fully and faithfully, with great plainness and evidence, that it may be understood and known by all; and with much certainty, without hesitation, as being, without controversy, undoubted truth; and with all boldness, not fearing men, or seeking to please them; and it should be constantly and continually spoken, in season, and out of season; and care should be taken that it be spoken consistently, and in an uniform manner, that there be no clashing and contradiction; and the duties of religion, which become sound doctrine, should be set in their true light, and proper place, as fruits of the grace of God, and to glorify him; these should be spoken out plainly, frequently insisted upon, and warmly and zealously urged, as being decent things, for the honour of God, the recommending of religion, the good of mankind, and the service of one another: as particularly. ~John Gill

Quoted verse:
2 Timothy 1:13
Hold fast the form of sound words, which thou hast heard of me, in faith and love which is in Christ Jesus.

What have we been learning through First and Second Timothy and now Titus? Immerse yourself into the Word of God, prove these doctrines and truths and conform to them.

This is the lesson of verse 1.