Authentic Supplication Number 242.

And `Aa’ishata  said: “The Messenger of Allah used to bring the little boys, and then he would ask Allah for blessing for them, and yuhannikukum (252)”.

Footnotes.
(252) Yuhannikukum means that he would make tahneek for them which is the rubbing of the lower jay with softened date.

Reporters.
Reported by Abu Dawood. Al-Albani said that it was sound according to the conditions of Al-Bukhari, and Muslim, and that it was also reported by Muslim. Al-Albani included this hadeeth in The Authentic of Good Sayings as #169.