Musannaf Ibn Abi Shaybah

Hazrat Hayan bin Umair says that I was with Qais bin Abad. He saw a man who was praying with his hands placed under his neck. He said, "Go to this companion of yours and tell him to remove his hand from the place as if it were in shackles." I went to him and told him that Hazrat Qais is saying to remove your hand from the place as if it were in shackles. So he removed his hand from there.