In his book Al-Kifaya fi 'Ilm al-Rawa'iya (Sufficiency in the Science of Narration), Al-Khatib al-Baghdadi wrote a chapter entitled "On Justice and Its Rulings," in which he said: "Umar ibn al-Khattab, may Allah be pleased with him, said that people were judged by revelation during the time of the Messenger of Allah, peace be upon him, and that revelation has ceased. Now I judge you by what is apparent in your deeds. Whoever shows us good, we trust him and draw him close to us, and we have no knowledge of his secret deeds; Allah will judge him for his secret deeds. Whoever shows us evil, we do not trust him and do not believe him, even if he says that his secret deeds are good.

It was narrated from Al-Hussein ibn Ali, may Allah be pleased with him, that the Prophet, peace be upon him, said: "Whoever treats people without oppressing them, speaks to them without lying to them, and makes promises to them without breaking them, then he has perfected his manhood, his justice has become apparent, his brotherhood has become obligatory, and his backbiting has become forbidden."