Charles Ellicott Commentary Leviticus 19:16

"Thou shalt not go up and down as a talebearer among thy people: neither shalt thou stand against the blood of thy neighbor: I am Jehovah." — Leviticus 19:16 (ASV)

You shall not go up and down as a tale-bearer. —Better, You shall not go about slandering, as the Authorised Version has it in Jeremiah 6:28; Jeremiah 9:4; Ezekiel 22:9, Margin. While giving just evidence in a court of justice is demanded by the law, it prohibits the circulation of slanderous reports about our neighbors. This dangerous habit, which has ruined the character and destroyed the life of many an innocent person (1 Samuel 22:9, 1 Samuel 22:18; Ezekiel 22:9, and so on), was denounced by the spiritual authorities in the time of Christ as the greatest sin.

Three things they declared remove a person from this world and deprive them of happiness in the world to come—idolatry, incest, and murder, but slander surpasses them all. It kills three persons with one act: the person who slanders, the person who is slandered, and the person who listens to the slander. Hence the ancient Chaldee Version of Jonathan translates this clause: You shall not follow the thrice accursed tongue, for it is more fatal than the double-edged devouring sword. (Compare also to Sirach 28:14)

Neither shall you stand against the blood. —This part of the verse is evidently designed to express another line of conduct by which our neighbor's life might be endangered. In the former clause, “the going about” with slanderous reports endangered the life of the slandered person; here, “the standing still” is prohibited when it involves fatal consequences.

The administrators of the law during the Second Temple, translating this clause literally, you shall not stand still by the blood, and so on, interpreted it to mean that if we see anyone in danger of their life (that is, drowning, being attacked by robbers or wild beasts, and so on), we are not to stand still by it while their blood is being shed, but are to render them assistance, even at the peril of our own life.

Or, if we know that someone has shed the blood of their fellow creature, we are not to stand silently by while the case is before the tribunal. Hence, the Chaldee Version of Jonathan renders it: You shall not keep silent the blood of your neighbor when you know the truth in judgment. Others, however, interpret it as meaning to come forward and try to obtain a false sentence of death against our neighbors, so that this phrase is similar in meaning to Exodus 23:1; Exodus 23:7.