Abdullah bin Abu Bakr says: My father and Urwah bin Zubair had a discussion about which actions require ablution (i.e., what things break wudu), so Urwah mentioned among them touching the private parts. My father said about this matter that it is something about which I have not heard anything. Urwah said: That is how it is. Marwan bin Hakam has informed me that he heard Lady Busrah bint Safwan (may Allah be pleased with her) narrate this, she says: I heard the Prophet Muhammad (peace and blessings be upon him) say: "Whoever touches his private part should perform ablution." So I said to Marwan: I wish you would send a message to that lady. He sent a message, and I was present at that time. Perhaps he sent a man or a soldier, so the messenger returned from that lady and said: She has narrated this, the Prophet Muhammad (peace and blessings be upon him) said: "Whoever touches his private part should perform ablution."