Sayyiduna Abdullah (may Allah be pleased with him) narrates: I was among the goats of Uqbah bin Abi Mu'ayt when the Messenger of Allah (peace and blessings be upon him) came to me and said: "O boy, do you have any milk?" I said: "Yes, but I am entrusted." He (peace and blessings be upon him) said: "Bring me a goat that no male has mounted." So I brought a young goat or a kid, and he (peace and blessings be upon him) began passing his hand over the udder and supplicating until milk came down into it. Abu Bakr (may Allah be pleased with him) brought a stone, and he (peace and blessings be upon him) milked into it, then handed it to Abu Bakr (may Allah be pleased with him) and he drank, then he (peace and blessings be upon him) drank after him. Then he said to the udder: "Shrink, by the permission of Allah," and it shrank and became as it had been before.
Afterwards I came to the Prophet (peace and blessings be upon him) and said: "Teach me some of this Qur'an, or of this speech." He (peace and blessings be upon him) passed his hand over my head and said: "You are a boy who is taught." So I took seventy surahs from his mouth (peace and blessings be upon him), about which no human being disputes with me.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 8424