Musannaf Ibn Abi Shayba 1:972

Ibn ‘Ulayyah narrated to us, from Muhammad ibn Ishaq, who said: Sa‘id ibn ‘Ubayd ibn al-Sabbaq narrated to us, from his father, from Sahl ibn Hunayf, who said: I used to experience severe difficulty from *madhy* (prostatic fluid), and I would perform *ghusl* (full ritual washing) frequently because of it. So I asked the Messenger of Allah, may Allah bless him and grant him peace, and he said: "It is sufficient for you in that regard to perform *wudu* (ablution)."