Musannaf Ibn Abi Shayba 3:3909

Ibn Mahdi narrated to us, from Sufyan, from Jabir, from Abu al-Duha, that water was dropped into the eyes of Ibn Abbas. It was said to him, "Will you lie on your back for seven [days] and not pray except while lying on your back?" So he sent to Aisha and Umm Salama and asked them, and they forbade him [from doing so].