Hear thou, my son, and be wise, and guide thy heart in the (i) way.
(i) In the observation of God's commandments.

Hear thou, my son, and be wise,.... Hear the instruction of a father, of the word of Wisdom, of the ministers of the Gospel, which is the way to be wise unto salvation; faith comes by hearing; spiritual wisdom, and an increase of it; the Spirit of God, and his gifts and graces;
and guide thine heart in the way; in the way of the Lord, in the way of wisdom and understanding, in the way of truth and faith, in the way of religious worship, in the way of the commandments and ordinances of the Lord; in all which the heart should be guided and directed, or otherwise it will be of no avail.

The gracious Saviour who purchased pardon and peace for his people, with all the affection of a tender parent, counsels us to hear and be wise, and is ready to guide our hearts in his way. Here we have an earnest call to young people, to attend to the advice of their godly parents. If the heart be guided, the steps will be guided. Buy the truth, and sell it not; be willing to part with any thing for it. Do not part with it for pleasures, honours, riches, or any thing in this world. The heart is what the great God requires. We must not think to divide the heart between God and the world; he will have all or none. Look to the rule of God's word, the conduct of his providence, and the good examples of his people. Particular cautions are given against sins most destructive to wisdom and grace in the soul. It is really a shame to make a god of the belly. Drunkenness stupifies men, and then all goes to ruin. Licentiousness takes away the heart that should be given to God. Take heed of any approaches toward this sin, it is very hard to retreat from it. It bewitches men to their ruin.

guide . . . way--or direct thy thoughts to a right course of conduct (compare Proverbs 4:4; Proverbs 9:6).

Among the virtues which flow from the fear of God, temperance is made prominent, and the warning against excess is introduced by the general exhortation to wisdom:
19 Hear thou, my son, and become wise,
And direct thy heart straight forward on the way.
20 And be not among wine-drinkers,
And among those who devour flesh;
21 For the drunkard and glutton become poor,
And sleepiness clotheth in rags.
The אתּה, connected with שׁמע, imports that the speaker has to do with the hearer altogether by himself, and that the latter may make an exception to the many who do not hear (cf. Job 33:33; Jeremiah 2:31). Regarding אשּׁר, to make to go straight out, vid., at Proverbs 4:14; the Kal, Proverbs 9:6, and also the Piel, Proverbs 4:14, mean to go straight on, and, generally, to go. The way merely, is the one that is right in contrast to the many byways. Fleischer: "the way sensu eximio, as the Oriental mystics called the way to perfection merely (Arab.) âlaṭryḳ; and him who walked therein, âlsâlak, the walker or wanderer."
(Note: Rashi reads בדרך לבך (walk), in the way of thy heart (which has become wise), and so Heidenheim found it in an old MS; but בדרך is equivalent to בדרך בינה, Proverbs 9:6.)
אל־תּתי ב, as at Proverbs 22:26, the "Words of the Wise," are to be compared in point of style. The degenerate and perverse son is more clearly described, Deuteronomy 21:20, as זולל וסבא. These two characteristics the poet distributes between 20a and 20b. סבא means to drink (whence סבא, drink = wine, Isaiah 1:22) wine or other intoxicating drinks; Arab. sabâ, vinum potandi causa emere. To the יין here added, בּשׂר in the parallel member corresponds, which consequently is not the fleshly body of the gluttons themselves, but the prepared flesh which they consume at their luxurious banquets. The lxx incorrectly as to the word, but not contrary to the sense, "be no wine-bibber, and stretch not thyself after picknicks (συμβολαῖς), and buying in of flesh (κρεῶν τε ἀγορασμοῖς)," whereby זללי is translated in the sense of the Aram. זבני (Lagarde). זלל denotes, intransitively, to be little valued (whence זולל, opp. יקר, Jeremiah 15:19), transitively to value little, and as such to squander, to lavish prodigally; thus: qui prodigi sunt carnis sibi; למו is dat. commodi. Otherwise Gesenius, Fleischer, Umbreit, and Ewald: qui prodigi sunt carnis suae, who destroy their own body; but the parallelism shows that flesh is meant wherewith they feed themselves, not their own flesh (בּשׂר למו, like חמת־למו, Psalm 58:5), which, i.e., its health, they squander. זולל also, in phrase used in Deuteronomy 21:20 (cf. with Hitzig the formula φάγος καὶ οἰνοπότης, Matthew 11:19), denotes not the dissolute person, as the sensualist, πορνοκόπος (lxx), but the συμβολοκόπος (Aquila, Symmachus, Theodotion), κρεωβόρος (Venet.), זלל בּסר (Onkelos), i.e., flesh-eater, ravenous person, glutton, in which sense it is rendered here, by the Syr. and Targ., by אסוט (אסיט), i.e., ἄσωτος. Regarding the metaplastic fut. Niph. יוּרשׁ (lxx πτωχεύσει), vid., at Proverbs 20:13, cf. Proverbs 11:25. נוּמה (after the form of בּוּשׁה, דּוּגה, צוּרה) is drowsiness, lethargy, long sleeping, which necessarily follows a life of riot and revelry. Such a slothful person comes to a bit of bread (Proverbs 21:17); and the disinclination and unfitness for work, resulting from night revelry, brings it about that at last he must clothe himself in miserable rags. The rags are called קרע and ῥάκος, from the rending (tearing), Arab. ruk'at, from the patching, mending. Lagarde, more at large, treats of this word here used for rags.

Guide - Order the whole course of thine affections and actions. In the way - In God's way.