Musannaf Ibn Abi Shayba 6:910

Abu Dawud al-Tayalisi narrated to us, from al-Aswad ibn Shayban, from Khalid ibn Numayr, who said: I was with al-Ahnaf at a funeral, and al-Ahnaf sat down, and I sat with him. When they finished burying him—and he was Dirar ibn al-Qa'qa' al-Tamimi—I saw al-Ahnaf reach his grave, so he stood over it. He began by praising him before supplicating for him. He said: "I swear by Allah, I knew you to be such and such," then he supplicated for him.