Is it necessary to repeat the adhkar (remembrances) of sleep if a person gets up for Fajr prayer and then returns to sleep, or if they get up for a brief task and then return to sleep? And is it obligatory to re-recite Surah Al-Mulk when sleeping during the day?

Adhkar (remembrances) of sleep that are restricted to the night, such as reciting the last two verses of Surat Al-Baqarah, are not to be recited before daytime sleep. As for those that are not restricted to the night, they can be recited before sleep, whether at night or during the day. If someone wakes up after reciting the adhkar for a need, they do not need to repeat them unless they wish to. The recitation of Surat Al-Mulk should be done at night, not during the day, and it is not restricted to immediately before sleep.