What does Proverbs 23:15 mean?

This is the twelfth of thirty wise sayings compiled by Solomon (Proverbs 22:17–21). Here, he speaks to his "son," possibly meaning a student. Teachers and parents feel a legitimate, godly sense of pride when their students and children make beneficial use of their lessons. This statement comes immediately after one of this book's many endorsements of proper child discipline (Proverbs 23:13–14). Proper, loving discipline directs a child towards godly wisdom (Proverbs 1:1–7; 3:1–5).

In most modern languages, references to the "heart" imply sentiments. That's also true in Scripture, though in the ancient world the heart was thought of as the seat of both intellect and emotions. Both sides are at work in this verse; a person with a "wise heart" is one whose thoughts and attitudes reflect the will of God (Romans 12:1–2). A parent who sees their children living sensibly and with godliness will feel a sense of happiness and joy.

The New Testament believer who is wise has the mind of Christ (1 Corinthians 2:14–16). Also, he detests sin and loves righteousness (Hebrews 1:9; Romans 6:11). He rejoices not in iniquity but in the truth (1 Corinthians 13:6). He loves God and God's Word (Colossians 3:16; 2 Timothy 3:16–17; 1 John 4:13–21). A wise son causes his parents to rejoice. The apostle John writes to "the elect lady and her children" (2 John 1:1) and says, "I rejoiced greatly to find some of your children walking in the truth, just as were commanded by the Father" (2 John 1:4). A father and mother experience extraordinary joy when they see their son or daughter walking in righteousness as good ambassadors for Jesus Christ. In contrast, it's heartbreaking to watch your children choose evil (Proverbs 17:25; 19:26; 28:7).