Proverbs 29:24

Whoso is partner with a thief hateth his own soul: he heareth cursing, and bewrayeth it not.
– Proverbs 29:24

The word for partner alludes to dividing the spoil, as it is used in Proverbs 16:19. A thief is obviously one who steals and is not a sympathetic case as in Proverbs 6:30. Proverbs opens with a warning against such a partnership (Proverbs 1:10-19). To join in with such evil doers is to hate your own life and to be taken in a snare (Proverbs 26:27; 29:6). It puts one in company with great fools (Proverbs 6:32; 8:36; 15:32; 20:2).

The cursing in the second line refers to swearing an oath. It appears only here in Proverbs, though it is used in the law to show that remaining silent when called to witness is a false witness (Leviticus 5:1). The word bewrayeth is an old word out of use today, but it and the underlying Hebrew word mean to expose, or make known. Such a fool has multiplied sin by dividing the spoil with the wicked and bearing false witness.