Sahih al-Bukhari, Volume 1, Book 4, Hadith 223 (USC-MSA) ⓘ

Narrated Um Qais bint Mihsin: I brought my young son, who had not started eating (ordinary food) to Allah's Messenger who took him and made him sit in his lap. The child urinated on the garment of the Prophet, so he asked for water and poured it over the soiled (area) and did not wash it.

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، قَالَ أَخْبَرَنَا مَالِكٌ، عَنِ ابْنِ شِهَابٍ، عَنْ عُبَيْدِ اللَّهِ بْنِ عَبْدِ اللَّهِ بْنِ عُتْبَةَ، عَنْ أُمِّ قَيْسٍ بِنْتِ مِحْصَنٍ، أَنَّهَا أَتَتْ بِابْنٍ لَهَا صَغِيرٍ، لَمْ يَأْكُلِ الطَّعَامَ إِلَى رَسُولِ اللَّهِ صلى الله عليه وسلم، فَأَجْلَسَهُ رَسُولُ اللَّهِ صلى الله عليه وسلم فِي حِجْرِهِ، فَبَالَ عَلَى ثَوْبِهِ، فَدَعَا بِمَاءٍ فَنَضَحَهُ وَلَمْ يَغْسِلْهُ‏.‏