Stand against the blood of thy neighbor - Either, to put his life in danger by standing up as his accuser (compare Matthew 26:60); or, to stand by idly when thy neighbor’s life is in danger. Whichever interpretation we adopt, the clause prohibits that which might interfere with the course of justice.
Related Commentaries of Leviticus 19:16
Leviticus 19:16
16 Thou shalt not go up and down as a talebearer among thy people: neither shalt thou stand against the blood of thy neighbour: I am the LORD.