Another continuous exhortation rather than a collection of maxims.

My son, if thine heart be wise,.... To that which is good; so as from it to understand in a spiritual and experimental manner things divine and heavenly; he may be said to have a wise heart who knows in some measure what his heart is, the wickedness, the original depravity and corruption, of it; the plague of his own heart; the weakness and inability of it to do that which is good; the insufficiency of his own righteousness to justify him before God; the poverty of his spirit, and the folly of his mind: and who also is wise unto salvation; that knows the way of peace, pardon, righteousness, and salvation by Christ; and who applies to him for the same; builds on him, the foundation; prizes and values him; rejoices in him, and gives him the glory of his salvation; receives his doctrines, and obeys his commands; takes up and makes a profession of him on right principles, and walks wisely, becoming his character and profession;
my heart shall rejoice, even mine; it shall certainly and greatly rejoice; these words are spoken either by Solomon, who had a wise heart himself, and that either to his son, for whom he desired the same, nothing being more rejoicing to pious parents than to see their children becomes wise, especially in spiritual things; or else to those that attended on him for instruction, who was a preacher in Jerusalem; and what is the joy and crown of rejoicing of ministers but their converts, and to see them walking in the truth? 1-Thessalonians 2:19, 3-John 1:4; or these words are spoken by Wisdom, that is, by Christ, to his children; who rejoices when he has found them, or when they are converted, and become wise in a spiritual sense, and walk worthy, whereby Wisdom is justified of her children, Luke 15:5; yea, there is joy in heaven, joy among the angels there, and even in the father of Christ, and of his people, Luke 15:7.

The pleasure afforded the teacher by the pupil's progress is a motive to diligence.

The following proverb passes from the educator to the pupil:
15 My son, if thine heart becometh wise,
My heart also in return will rejoice;
16 And my reins will exult
If thy lips speak right things.
Wisdom is inborn in no one. A true Arab. proverb says, "The wise knows how the fool feels, for he himself was also once a fool;"
(Note: The second part of the saying is, "But a fool knows not how a wise man feels, for he has never been a wise man." I heard this many years ago, from the mouth of the American missionary Schaufler, in Constantinople.)
and folly is bound up in the heart of a child, according to Proverbs 22:15, which must be driven out by severe discipline. 15b, as many others, cf. Proverbs 22:19, shows that these "words of the wise" are penetrated by the subjectivity of an author; the author means: if thy heart becomes wise, so will mine in return, i.e., corresponding to it (cf. גּם, Genesis 20:6), rejoice. The thought of the heart in Proverbs 23:15 repeats itself in Proverbs 23:16, with reference to the utterance of the mouth. Regarding מישׁרים, vid., Proverbs 1:5. Regarding the "reins," כּליות (perhaps from כּלה, to languish, Job 19:21), with which the tender and inmost affections are connected, vid., Psychologie, p. 268f.