Musannaf Ibn Abi Shayba 3:6065

Ibn Idris narrated to us, from ‘Asim ibn Kulayb, from his father, from Wa’il ibn Hujr, who said: I saw the Messenger of Allah (may Allah bless him and grant him peace) placing one of his elbows—the right one—upon his thigh. He formed a circle with the thumb and the middle finger, and he raised the one next to the thumb, supplicating with it.