Surah Al-Anfal 8:11

إِذْ يُغَشِّيكُمُ ٱلنُّعَاسَ أَمَنَةً مِّنْهُ وَيُنَزِّلُ عَلَيْكُم مِّنَ ٱلسَّمَآءِ مَآءً لِّيُطَهِّرَكُم بِهِۦ وَيُذْهِبَ عَنكُمْ رِجْزَ ٱلشَّيْطَـٰنِ وَلِيَرْبِطَ عَلَىٰ قُلُوبِكُمْ وَيُثَبِّتَ بِهِ ٱلْأَقْدَامَ

[Remember] when He overwhelmed you with drowsiness [giving] security from Him and sent down upon you from the sky, rain by which to purify you and remove from you the evil [suggestions] of Satan and to make steadfast your hearts and plant firmly thereby your feet.

Translation: Saheeh International

Tafsir

Remember when He caused slumber to overcome you as security against the fear that had befallen you from Him from God and sent down upon you water from the heaven to purify you thereby from minor and major ritual impurities; …

Excerpt from Tafsir al-Jalalayn, commentary on 8:11, via Quran.com. The reader has the full commentary and 9 more tafsirs.