Musannaf Ibn Abi Shaybah 23115 — What is uprightness among

Shurayh (may Allah have mercy on him) said: First make your claim, then add to it and elaborate on it fully, and then establish upright witnesses for it, for we have been commanded to judge with justice. And go and ask about him. If they say, 'Allah knows best,' then Allah knows best: they are afraid to say, 'He is dubious,' and the testimony of a dubious person is not accepted. And if they say, 'We know of him only that he is an upright Muslim,' then he is, if Allah wills, as they say, and his testimony is accepted.