Abu Dawud
General Behavior
Book Number: 036 / Hadith Number: 5087
Narated By 'Aisha, Ummul Mu'minin : Boys used to be brought to the Apostle of Allah (pbuh), and he would invoke blessings on them. Yusuf added: "and soften some dates and rub their palates with them". He did not mention "blessings".