(1) باب تَسْمِيَةِ الْمَوْلُودِ غَدَاةَ يُولَدُ، لِمَنْ لَمْ يَعُقَّ عَنْهُ، وَتَحْنِيكِهِ
Narrated `Aisha:
A boy was brought to the Prophet (ﷺ) to do Tahnik for him, but the boy urinated on him, whereupon the Prophet had water poured on the place of urine.
Reference: Sahih al-Bukhari 5468
In-book reference: Book 71, Hadith 2
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 7, Book 66, Hadith 377