Musnad Ahmad 32:1094

Ibrahim ibn Khalid narrated to us, Rabah narrated to us, from Ma'mar, from Thabit al-Bunani, from Anas ibn Malik, who said: "Shall I not pray for you the prayer of the Messenger of Allah, may Allah bless him and grant him peace?" So he prayed for them a good prayer, in which he did not prolong.