Woe unto you! You have cut the neck of your companion

Abu Bakrah (may Allah be pleased with him) reported that a man was mentioned in the presence of the Prophet (may Allah's peace and blessings be upon him) and another man praised him. So the Prophet (may Allah's peace and blessings be upon him) said: “Woe unto you! You have cut the neck of your companion,” repeating it several times. Then he said: “If one of you has to praise (another), let him say: ‘I reckon him to be as such and such' if he sees him to be like that, and Allah is the One Who will take account of him. No one can testify the purity of others against Allah."