LEV581 [This] commandment means that we should not remain silent when we observe someone behaving badly. [This often-overlooked commandment is so significant that the Talmud teaches, "Jerusalem was destroyed because its citizens didn't rebuke one another" (Shabbat 119b). Thus, no matter how elevated a society is--and Jerusalem has long been regarded as Judaism's premier city--if people don't effectively critique each other's ethical lapses, the society will deteriorate quickly.] Rather, we should speak to the person and point out what's wrong with his behavior (See the next chapter for ways to express criticism). The verse's second clause, "and not bear sin because of him," means that if we have the ability to influence someone who is acting improperly, and don't, then we share in responsibility for that person's misdeeds (See Nachmanides' commentary on this verse].