Muwatta Imam Malik (Riwayat Ibn al-Qasim)

Sayyiduna Ibn Umar (may Allah be pleased with them both) used to say that people say: If you sit for relieving yourself, then neither face the Qiblah nor Bayt al-Maqdis. Abdullah ibn Umar (may Allah be pleased with them both) said: I had climbed onto the roof of my house and saw that the Messenger of Allah (peace and blessings be upon him) was relieving himself facing Bayt al-Maqdis. Then he (Ibn Umar) said (to Wasi‘ ibn Hibban, may Allah have mercy on him): Perhaps you are among those people who pray on their buttocks? (Wasi‘ ibn Hibban, may Allah have mercy on him, said:) I said: By Allah! I do not know. (Imam Malik said:) That is, the person who prostrates but does not rise above the ground, rather he remains clinging to the ground while prostrating.