From Sahih Bukhari (Hadith 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
Reference: Bukhari 6002