Musnad Abu Ya'la al-Mawsili 150:405

Abu al-Rabi' narrated to us, Abu Shihab narrated to us, from al-Shaybani, from Abd al-Rahman ibn al-Aswad, from his father, from Aisha, who said: The Messenger of Allah (may Allah bless him and grant him peace) granted a concession regarding ruqyah (incantations) for the fever (or venomous sting).