Rashi on Leviticus 19:17/רש"י על ויקרא י״ט:י״ז

1ולא תשא עליו חטא [THOU SHALT IN ANY WISE REBUKE THY COMPANION] AND NOT BEAR A SIN ON ACCOUNT OF HIM — i. e. though rebuking him thou shalt not expose him to shame (lit., make his face grow pale) in public, in which case you will bear sin on account of him (cf. Sifra, Kedoshim, Chapter 4 8; Arakhin 16b).