Sahih al-Bukhari 5007

Narrated Abu Sa`id Al-Khudri:While we were on one of our journeys, we dismounted at a place where a slave girl came and said, "The chief of this tribe has been stung by a scorpion and our men are not present; is there anybody among you who can treat him (by reciting something)?" Then one of our men went along with her though we did not think that he knew any such treatment. But he treated the chief by reciting something, and the sick man recovered whereupon he gave him thirty sheep and gave us milk to drink (as a reward). When he returned, we asked our friend, "Did you know how to treat with the recitation of something?" He said, "No, but I treated him only with the recitation of the Mother of the Book (i.e., Al-Fatiha)." We said, "Do not say anything (about it) till we reach or ask the Prophet (ﷺ) so when we reached Medina, we mentioned that to the Prophet (in order to know whether the sheep which we had taken were lawful to take or not). The Prophet (ﷺ) said, "How did he come to know that it (Al-Fatiha) could be used for treatment? Distribute your reward and assign for me one share thereof as well