The ruling on the urine of a nursing infant and how to wash it Sahih Muslim 286b
Arabic hadith text
حَدَّثَنَا زُهَيْرُ بْنُ حَرْبٍ، حَدَّثَنَا جَرِيرٌ، عَنْ هِشَامٍ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ، قَالَتْ أُتِيَ رَسُولُ اللَّهِ صلى الله عليه وسلم بِصَبِيٍّ يَرْضَعُفَبَالَ فِي حِجْرِهِ فَدَعَا بِمَاءٍ فَصَبَّهُ عَلَيْهِ .
Translation
A'isha reported
A suckling babe was brought to the Messenger of Allah (way peace be upon him) and he urinated in his tap. He (the Holy Prophet) sent for water and poured it over.