Sunan an-Nasa'i, Book 1, Hadith 305 (In-Book) ⓘ
It was narrated that 'Aishah said: "A small boy was brought to the Messenger of Allah and he urinated on him, so he called for water and poured it on the place where the urine was."
أَخْبَرَنَا قُتَيْبَةُ، عَنْ مَالِكٍ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ، قَالَتْ أُتِيَ رَسُولُ اللَّهِ صلى الله عليه وسلم بِصَبِيٍّ فَبَالَ عَلَيْهِ فَدَعَا بِمَاءٍ فَأَتْبَعَهُ إِيَّاهُ .
also referenced under: Volume 1, Book 1, Hadith 304 (DarusSalam)