Musnad Abu Ya'la al-Mawsili 140:5

Abu Bakr ibn Abi Shaybah narrated to us, Waki' narrated to us, from al-A'mash, from Yazid al-Raqashi, from Anas, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "The children are the servants of the people of Paradise."