Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) said that the Prophet (peace and blessings be upon him) went out to the Quba mosque, and the Ansar came and began greeting him with salam. So I asked Bilal (may Allah be pleased with him): How did the Messenger of Allah (peace and blessings be upon him) reply to them? He said: "He would gesture with his hand like this."
Hadith Referenceالمعجم الكبير للطبراني / باب الباء / 1023