Sayyiduna Ali (may Allah be pleased with him) said: I used to have a lot of madhi (pre-seminal fluid). Since the daughter of the Prophet (peace and blessings be upon him) was married to me, I felt shy to ask the Prophet (peace and blessings be upon him) about this issue myself. So I told a man to ask the Prophet (peace and blessings be upon him) about this issue. So he asked about it, and the Prophet (peace and blessings be upon him) said: "Such a person should wash his private part and perform wudu."