Sayyiduna Abdullah bin al-Harith (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) would line up Abdullah, Ubaydullah and Kathir, the sons of Sayyiduna Abbas (may Allah be pleased with him), and then say: Whoever reaches me first will get such-and-such. So they (the children) would come running and fall upon his back and chest, and he would kiss them and hug them to himself.
Imam Ahmad recorded this narration, and its chain is hasan (good).