Musnad Abu Ya'la al-Mawsili 108:146

On the authority of Jabir, he said: I had a maternal uncle from the Ansar who used to perform ruqyah (incantations) for snakebites. The Messenger of Allah (peace and blessings of Allah be upon him) forbade ruqyah. So my uncle came to him and said: "O Messenger of Allah, you have forbidden ruqyah, and I used to perform ruqyah for snakebites." The Messenger of Allah said: "Present it to me." He said: "So he presented it to him." He said: "There is no harm in this; these are from the covenants."