Qabus al-Shaybani (may Allah have mercy on him) narrated from his father, who said: Umm al-Fadl (may Allah be pleased with her) came to the Messenger of Allah (peace and blessings be upon him) and said: "I have seen part of your body in my house." He (peace and blessings be upon him) said: "You have seen a good dream. Fatimah will give birth to a son, and you will nurse him with the milk of Qutham." She said: So she brought him, carrying him, to the Prophet (peace and blessings be upon him). She took him and placed him in his (peace and blessings be upon him) lap, and he urinated, so she slapped him with her hand. He (peace and blessings be upon him) said: "You have hurt my son, may Allah have mercy on you!" She said: "Give me your waist-wrapper so that we may wash it." He (peace and blessings be upon him) said: "The urine of a girl is washed, and water is sprinkled over the urine of a boy."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21501