Musnad Ahmad 23:2

Jarir narrated to us, from Yazid ibn Abi Ziyad, from Abdullah ibn al-Harith, who said: The Messenger of Allah (peace and blessings of Allah be upon him) used to line up Abdullah, Ubaydullah, and Kathir, the sons of al-Abbas, and then say: "Whoever reaches me first, for him is such and such." He said: So they would race toward him, and they would fall upon his back and his chest, and he would kiss them and embrace them.