And Muhammad ibn al-Muthanna narrated to us, saying: Muhammad ibn Abdullah al-Ansari narrated to us, saying: Hisham ibn Hassan narrated to us, saying: Humayd ibn Hilal narrated to us, from Abu Burda, from Abu Musa al-Ash'ari. (Another chain:) And Muhammad ibn al-Muthanna narrated to us, saying: Abd al-A'la narrated to us — and this is his narration — saying: Hisham narrated to us, from Humayd ibn Hilal, who said: I know it only from Abu Burda, from Abu Musa, who said: A group of the Emigrants and the Helpers differed on this matter. The Helpers said: "The ritual bath is obligatory only from the ejaculation of fluid or from water." The Emigrants said: "Rather, when the two circumcised parts meet, the ritual bath has become obligatory." Abu Musa said: I will spare you this [dispute]. So I stood and sought permission to enter upon Aisha, and permission was granted to me. I said to her: "O mother — or O Mother of the Believers — I wish to ask you about something, and I am too shy before you." She said: "Do not be shy to ask me about what you would have asked your own mother who bore you, for I am your mother." I said: "What makes the ritual bath obligatory?" She said: "You have come to one who knows. The Messenger of Allah, peace and blessings be upon him, said: 'When he sits between her four parts and the circumcision touches the circumcision, then the ritual bath has become obligatory.'"