Musnad Ahmad 785:15

Hashim ibn al-Qasim narrated to us, Sharik narrated to us, from Ya'la ibn 'Ata, from 'Amr ibn al-Sharid, from his father, who said: A leper man from Thaqif came to the Prophet, peace and blessings of Allah be upon him, to pledge allegiance to him. I came to the Prophet, peace and blessings of Allah be upon him, and mentioned that to him. He said: "Go to him and inform him that I have accepted his pledge of allegiance, so let him return."