Children used to be brought to the Messenger of Allah ﷺ and he would invoke blessings upon them. Yusuf added that he would also rub their palates with chewed dates, but he did not mention the invocation of blessings.
حدثنا عثمان بن أبي شيبة حدثنا محمد بن فضيل ح و حدثنا يوسف بن موسى حدثنا أبو أسامة عن هشام بن عروة عن عروة
كان رسول الله ﷺ يؤتى بالصبيان فيدعو لهم بالبركة زاد يوسف ويحنكهم ولم يذكر بالبركة
No references are available.
[Its chain of transmission is sahih] Bukhari narrated it in the Book of Supplications, Chapter on Supplicating for Children with Blessing and Wiping Their Heads, no. 6355, and Muslim narrated it in the Book of Purification, Chapter on the Ruling Regarding the Urine of a Nursing Infant and How to Wash It, no. 286, from the hadith of Hisham bin Urwa, with the same chain.