Musannaf Ibn Abi Shayba 33:1453

Affan narrated to us, he said: Hammad bin Salamah narrated to us, he said: Humayd informed us, he said: We used to come to Anas, and Thabit was with us. Whenever he passed by a mosque, he would pray in it. So we would come to Anas, and he would say: "Where is Thabit? Where is Thabit? Where is Thabit? Indeed, Thabit is a little creature that I love."