Sahih Muslim , Book 25, Hadith 5347 (USC-MSA) ⓘ
'A'isha reported that the new-born infants were brought to Allah's Messenger. He blessed them and rubbed their palates with dates.
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ نُمَيْرٍ، حَدَّثَنَا هِشَامٌ، - يَعْنِي ابْنَ عُرْوَةَ - عَنْ أَبِيهِ، عَنْ عَائِشَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يُؤْتَى بِالصِّبْيَانِ فَيُبَرِّكُ عَلَيْهِمْ وَيُحَنِّكُهُمْ .
also referenced under: Book 38, Hadith 34 (In-Book) & Hadith 2147 (Reference)