Tafsir of Al-Qamar 54:45

(Sihzam al-jam'): A refutation of their saying "that." The sin is for emphasis, meaning they shall all be defeated, absolutely.

(Wa yuwallun al-dubur): Meaning their backs. It has also been recited as such. The use of the singular [referring to al-dubur] is intended to denote the generic category, applicable to many, while observing the rhyme scheme and the structure of the corresponding verses, or because it is interpreted as "every one of them turns his back," similar to the phrase "The Prince gave us a garment," where the aforementioned observance [of rhyme] is also present.

This occurred on the day of Badr and is among the signs of Prophethood, for this verse is Meccan and was revealed at a time when Jihad had not been ordained, nor was there any fighting. For this reason, Umar—may Allah be pleased with him—said: "On the day it was revealed, I asked: 'Which gathering will be defeated?'" [referring to the gathering of the disbelievers], for he had not engaged in fighting any of them at that time. The report has already preceded. From what we have pointed out, it is known that the statement of al-Tibi regarding this narration is questionable, because the interrogative of denial in "Or do they say..." indicates that those who are defeated are the ones mentioned [in the text], and his criticism stems from heedlessness regarding the intent of Umar—may Allah be pleased with him.

Abu Haywah, Musa al-Aswari, and Abu al-Barhas recited it as satahzamu al-jam'—with a fat'hah on the ta and a kasrah on the za—addressing the Messenger of Allah (may Allah bless him and grant him peace), with al-jam' in the accusative case as the object. Abu Haywah and Ya'qub also recited it as sanahzamu—with a nun carrying a fat'hah and a kasrah on the za—attributing the action to the pronoun of majesty [We]. From Abu Haywah and Ibn Abi 'Ablah, it is narrated as sayahzamu al-jam'—with a fat'hah on the ya, in the active voice, with al-jam' in the accusative—meaning: "Allah the Exalted shall defeat the gathering." Abu Haywah and Dawud ibn Abi 'Amr recited tawalluna with a ta [indicating the second person].