Jamieson, Fausset and Brown on Leviticus 19:17

17. thou shalt in any wise rebuke thy neighbour--Instead of cherishing latent feelings of malice or meditating purposes of revenge against a person who has committed an insult or injury against them, God's people were taught to remonstrate with the offender and endeavor, by calm and kindly reason, to bring him to a sense of his fault.

not suffer sin upon him--literally, "that ye may not participate in his sin."