Sayyiduna Abdullah bin Mas’ud (may Allah be pleased with him) says: I used to graze the goats of the family of Abi Mu’it. The Prophet (peace and blessings be upon him) came, and with him was Sayyiduna Abu Bakr (may Allah be pleased with him). They said:“Boy! Do you have any milk?”I said: Yes! But I am entrusted (with these goats). Sayyiduna Abu Bakr (may Allah be pleased with him) said: Do you have any goat with which a male goat has not mated? I said: Yes! A goat without udders. They said: Peace be upon you. Then the Prophet (peace and blessings be upon him) passed his hand over the place of its udders, and though it had no udders, suddenly milk came into its udders and they became full. So I brought a hollowed-out stone to the Prophet (peace and blessings be upon him), and he milked it into that, then gave Sayyiduna Abu Bakr (may Allah be pleased with him) to drink, and gave me to drink as well. Then he said to the udders:“Shrink.”So they shrank as they were before. When I saw this from the Prophet (peace and blessings be upon him), I said: Teach me this as well. So the Prophet (peace and blessings be upon him) passed his hand over my head and said:“May Allah bless you, you are a learned boy.”So I became Muslim and came to the Prophet (peace and blessings be upon him), and we were with him at Hira, and Surah Mursalat was revealed, so I took it, it was fresh from the mouth of the Prophet (peace and blessings be upon him). Then I memorized seventy surahs from the Prophet (peace and blessings be upon him), and the rest of the Qur’an I took from the companions (may Allah be pleased with them) of the Prophet (peace and blessings be upon him).