Musannaf Ibn Abi Shayba 36:490

Ja'far ibn 'Awn narrated to us, from Ibn Jurayj, from 'Ata', who said: It reached us that when the Messenger of Allah (may Allah bless him and grant him peace) died, the people began to enter, pray over him, and then leave, and others would enter likewise. He said: I said to 'Ata', "Do they pray and supplicate?" He said: "They pray and seek forgiveness."