Musnad Ahmad 25:891

Abu Ja'far al-Mada'ini narrated to us, he said: 'Abbad ibn al-'Awwam informed us, from Muhammad ibn Ishaq, Husayn ibn 'Abd Allah narrated to us, from 'Ikrimah, from Ibn 'Abbas, he said: Umm al-Fadl, daughter of al-Harith, came with Umm Habibah, daughter of al-'Abbas, and placed her in the lap of the Messenger of Allah, may Allah bless him and grant him peace. She urinated, so Umm al-Fadl snatched her away and struck her between her shoulder blades. Then she snatched her away, and the Messenger of Allah, may Allah bless him and grant him peace, said: "Give me a vessel of water." He poured it over the place where she had urinated, then he said: "Make the water follow the path of the urine."