Musannaf Ibn Abi Shayba 27:129

Muhammad ibn Fudayl narrated to us, from Qudama al-Amiri, from Jasra, from Abu Dharr, who said: I heard the Messenger of Allah (may Allah bless him and grant him peace) while he was praying one night, and he was repeating a verse until morning, bowing with it and prostrating with it: "If You punish them, then indeed they are Your servants." I said: "O Messenger of Allah, you kept repeating this verse until morning." He said: "I asked my Lord for intercession for my nation, and it is attainable for whoever does not associate anything with Allah."