as shown by the fact that he would make no prostration on its account if he omitted it deliberately or on the basis of independent legal reasoning. An act for which a substitute has been prescribed, although the act itself is not obligatory, is different. Deliberately omitting it or deliberately doing something that has no prescribed place in the prayer invalidates the prayer.
(The Inward Application of the Sittings and Their Rulings)
He distinguished the middle sitting, the sitting for rest, the sitting between the two prostrations in each unit of prayer, and the final sitting. The rulings for all these differ. Their inward application concerns the Cloud, the Throne, the lowest heaven, and the earth, where the servant sits in his place of sitting. The Cloud corresponds to the sitting between the two prostrations, the Throne to the final sitting, and the heaven to the middle sitting. My sitting on earth, wherever I may be among my places of sitting, corresponds to the sitting for rest.
When someone sits in an odd-numbered unit of his prayer, the ruling is different from that of the middle sitting. He has no authorization to omit the middle sitting, and he has authorization to sit for rest. If he deliberately sits for rest, he has deliberately done what he was authorized to do, and his prayer remains valid. If, meaning to stand, he forgetfully sits in an odd-numbered unit of his prayer, he prostrates on account of his forgetfulness. The sitting itself does not occasion the prostration.
He receives the reward for sitting and the reward for what he forgot by virtue of the prostration for forgetfulness, which is a humiliation for Satan. He also has the reward of one who does injury to God’s enemy and his own. For God says, “They set foot in no place that enrages the unbelievers and gain no advantage over an enemy without a righteous deed being recorded for them for it” [al-Tawbah 9:120]. Satan is among the unbelievers
Notes
Translator’s note TN1887-1: “The Cloud” renders al-ʿamāʾ, a cosmological term. The author pairs four ritual sittings with the Cloud, the Throne, the lowest heaven, and the earth.