The Book of Purification
2/31. Chapter:
The ruling on the urine of a nursing infant and how to wash it
Sahih Muslim
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، وَأَبُو كُرَيْبٍ قَالاَ حَدَّثَنَا عَبْدُ اللَّهِ بْنُ نُمَيْرٍ، حَدَّثَنَا هِشَامٌ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ، زَوْجِ النَّبِيِّ صلى الله عليه وسلم أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يُؤْتَى بِالصِّبْيَانِ فَيُبَرِّكُ عَلَيْهِمْ وَيُحَنِّكُهُمْ فَأُتِيَ بِصَبِيٍّ فَبَالَ عَلَيْهِ فَدَعَا بِمَاءٍ فَأَتْبَعَهُ بَوْلَهُ وَلَمْ يَغْسِلْهُ .
A'isha, the wife of the Apostle (ﷺ) said: Babies were brought to the Messenger of Allah (ﷺ) and he blessed them, and after having chewed (something, e. g. dates or any other sweet thing) he rubbed there with their soft palates. A baby was brought to him and he passed water over him (over his garment), so he asked water to be brought and sprinkled it, but he did not wash it.
Reference : Sahih Muslim 286aIn-book reference : Book 2, Hadith 128USC-MSA web (English) reference : Book 2, Hadith 560