The Messenger of Allah ﷺ said regarding the urine of a nursing infant, "The urine of a baby boy is sprinkled with water, and the urine of a baby girl is washed."
إن رسول الله ﷺ قال في بول الغلام الرضيع: ينضح من بول الغلام، ويغسل من بول الجارية.
Reported by Abu Dawud (378), and this is his wording, and Tirmidhi (610) and Ibn Majah (525), all of them through the route of Muaz bin Hisham, who said, "My father narrated to me," from Qatada, from Abu Harb bin Abu Aswad Deeli, from his father, from Ali, who said what has already been mentioned.Its chain of transmission is sahih, except that there is disagreement about whether it is raised to the Prophet or stopped at the companion, and the correct view is that it is raised to the Prophet. Tirmidhi said, "Hasan sahih. Hisham Dastawai raised this hadith from Qatada to the Prophet, while Saeed bin Abu Aruba narrated it from Qatada as stopped and did not raise it to the Prophet."Munziri said, "Bukhari said, Saeed bin Abu Aruba does not raise it to the Prophet, while Hisham Dastawai does raise it, and he is a reliable memorizer."Ibn Khuzayma (1/144) and Hakim (1/165, 166) also graded it sahih. For more, see Minna Kubra (1/270).