Musannaf Ibn Abi Shaybah 27949 — A man praising another man

Abd al-Rahman bin Abi Bakrah said that his father, Sayyiduna Abu Bakrah (may Allah be pleased with him), said: Someone praised a man in the presence of the Messenger of Allah (peace and blessings be upon him). At that the Prophet (peace and blessings be upon him) said to the one praising, several times: "Woe to you, you have cut your companion's neck." Then he (peace and blessings be upon him) said: "If one of you must praise his brother, let him say: 'I think him to be so, and I do not declare anyone pure before Allah.'"