What does Proverbs 20:17 mean?

This verse sounds a warning against stealing. Like many sins, there is a temporary pleasure involved (Proverbs 9:17). But the consequences of that sin will come, eventually. Those results can be intensely bitter. Most people have, at some point, discovered something hard in a soft bite of food while chewing. The experience can be surprising and painful. Some have even broken a tooth biting down on a hard object. One can only imagine what it would be like to start chewing a sweet, soft piece of bread, only to have it suddenly turn into rocks. Yet this is what sin does: promising freedom and pleasure (Genesis 3:4–5) but leading to suffering and slavery (Genesis 3:16–19; Romans 6:17–18; James 1:13–18).

A related English proverb is the phrase "crime doesn't pay." Obviously, people commit many crimes because it's a way of making money. The point of the English expression, as well as Solomon's proverb, is that the eventual consequences greatly outweigh the short-term benefits.

Scripture records a drastic example of this, when Achan looked on what God had said was off-limits. Rather than following the command to destroy everything in Jericho, he took "a beautiful cloak from Shinar, and 200 shekels of silver, and a bar of gold weighing 50 shekels" (Joshua 7:21). After gaining what seemed so attractive, Achan hid the loot in his tent. However, his sin cost him his life. According to Johsua 7:22–25, messengers from Joshua ran to Achan's tent, retrieved the stolen items, and laid them down before the Lord. Then Joshua and the people of Israel took Achan, the illicit goods, and Achan's sons and daughters—all accomplices in the theft—to the Valley of Achor, where they put Achan and his family to death by stoning.