Language:
كتاب الأدب
78  
Good Manners and Form (Al-Adab)
(21)
Chapter: To take a child in one's lap
(21)
باب وَضْعِ الصَّبِيِّ فِي الْحِجْرِ
Sahih al-Bukhari 6002

Narrated `Aisha:

The Prophet (ﷺ) took a child in his lap for Tahnik (i.e. he chewed a date in his mouth and put its juice in the mouth of the child). The child urinated on him, so he asked for water and poured it over the place of the urine.

حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، عَنْ هِشَامٍ، قَالَ أَخْبَرَنِي أَبِي، عَنْ عَائِشَةَ، أَنَّ النَّبِيَّ صلى الله عليه وسلم وَضَعَ صَبِيًّا فِي حِجْرِهِ يُحَنِّكُهُ، فَبَالَ عَلَيْهِ، فَدَعَا بِمَاءٍ فَأَتْبَعَهُ‏.‏
Reference : Sahih al-Bukhari 6002
In-book reference : Book 78, Hadith 33
USC-MSA web (English) reference : Vol. 8, Book 73, Hadith 31
  (deprecated numbering scheme)