—the mosque and keeping it clean. Ibn Abī Shaybah likewise relates that the Messenger of Allah ﷺ “used to pursue the dust of the mosque with a palm-stalk.”

I say: This ḥadīth shows that purifying and perfuming the mosque are obligatory, for the Prophet ﷺ commanded both, and a command denotes obligation. Ibn Ḥazm accepted this conclusion with respect to the first of the two but not the second, saying (4/239):

“Prayer niches in mosques are disliked; sweeping them is obligatory, while perfuming them is recommended.”

I say: I do not know what led him to treat the command to perfume as merely recommended. Allah knows best.

He ﷺ also said, “The rewards of my ummah were presented to me—even the mote of dust a man removes from the mosque….” The report continues: “…and the sins of my ummah were likewise shown to me, and I found no sin greater than a surah—or a single verse—of the Quran that is given to a man and then forgotten by him.”

It was recorded by Abū Dāwūd (1/76) and al-Tirmidhī (2/150). Both of them said: “‘Abd al-Wahhāb ibn ‘Abd al-Ḥakam al-Warrāq al-Baghdādī narrated to us; ‘Abd al-Majīd ibn ‘Abd al-‘Azīz narrated to us, from Ibn Jurayj, from al-Muṭṭalib ibn Ḥanṭab, from Anas, in a marfū‘ report.” Al-Tirmidhī remarked, “This is a singular ḥadīth; we do not know it except through this route,” and added, “I mentioned it to Muḥammad ibn Ismā‘īl—meaning al-Bukhārī—but he did not recognize it and considered it odd.”