Musnad Ahmad 1077:13

Hajjaj narrated to us, Layth—meaning Ibn Sa’d—narrated to us, ‘Aqil narrated to me, from Ibn Shihab, from ‘Abdullah ibn Tha’labah ibn Su’ayr al-‘Udhri—and the Messenger of Allah, peace and blessings of Allah be upon him, had wiped his face, and he had met the companions of the Messenger of Allah, peace and blessings of Allah be upon him—he said: They used to forbid me from kissing, fearing that I might approach more than that. Then, the Muslims today forbid it, and one of them says: "Indeed, the Messenger of Allah, peace and blessings of Allah be upon him, had from the protection of Allah what no one else had."