Musannaf Ibn Abi Shayba 13:3044

Abu Bakr narrated to us, he said: Hushaym narrated to us, from Isma'il ibn Salim, he said: I heard al-Sha'bi, and he was asked about a judge who judged with injustice. Al-Sha'bi said: As for injustice, I do not speak regarding it, [except to] say that it is not befitting for him to act unjustly. And regarding any judge who has judged, if a judge comes after him, he said: It is befitting for him to examine his judgment and take charge of that which he had taken charge of.