Sunan an-Nasai 15040
In-book no 304أَخْبَرَنَا 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 .
It was narrated that 'Aishah said: "A small boy was brought to the Messenger of Allah (ﷺ) and he urinated on him, so he called for water and poured it on the place where the urine was."