play the ball, not the man
Definition:  when someone has done something wrong, people should not criticize/disparage that person but criticize the act that was done
Usage:  sorry sir, may you please focus on my schoolwork and not me; I feel like you are attacking me personally, so please play the ball and not the man

SEPEDI
Translation:  bapala kgwele e sego motho
Proverb: a go kgalwe tšhipa e sego mmolayi wa yona

XITSONGA
Translation:  tlanga bolo u nga tlangi munhu
Proverb: bana mpfundla u tshika xihlahla

TSHIVENḒA
Translation:  tamba bola hu si ni munna
Proverb: kha i ponde i sie marambo