Musannaf Ibn Abi Shaybah 5366 — A man giving the salam when he arrives

Al-Hakam and Hammad said, concerning a man who enters the mosque on Friday after the imam has come out: He should give the greeting of salam, and the people should return his greeting. When he sneezes, they should say 'Yarhamuk Allah' (may Allah have mercy on you) to him.