إِذْ يُغَشِّيكُمُ النُّعَاسَ أَمَنَةً مِنْهُ وَيُنَزِّلُ عَلَيْكُمْ مِنَ السَّمَاءِ مَاءً لِيُطَهِّرَكُمْ بِهِ وَيُذْهِبَ عَنْكُمْ رِجْزَ الشَّيْطَانِ وَلِيَرْبِطَ عَلَى قُلُوبِكُمْ وَيُثَبِّتَ بِهِ الْأَقْدَامَ ﴿۱۱﴾ إِذْ يُوحِي رَبُّكَ إِلَى الْمَلَائِكَةِ أَنِّي مَعَكُمْ فَثَبِّتُوا الَّذِينَ آمَنُوا سَأُلْقِي فِي قُلُوبِ الَّذِينَ كَفَرُوا الرُّعْبَ فَاضْرِبُوا فَوْقَ الْأَعْنَاقِ وَاضْرِبُوا مِنْهُمْ كُلَّ بَنَانٍ ﴿۱۲﴾

﴾11﴿ Iz yughashsheekumun nu'assa amanatam minhu wa yunazzilu 'alaikum minas samaaa'i maaa'al liyutah hirakum bihee wa yuzhiba 'ankum rijzash Shaitaani wa liyarbita 'ala quloobikum wa yusabbita bihil aqdaam
﴾12﴿ Iz yoohee Rabbuka ilal malaaa'ikati annee ma'akum fasabbitul lazeena aamanoo; sa ulqee fee quloobil lazeena kafarur ru'ba fadriboo fawqal a'naaqi wadriboo minhum kulla banaan

﴾11﴿ When Allah, the Exalted, covers you with a robe as a protection from Himself, and sends down water upon you from the sky to purify you with it And remove from you the evil of Satan, and that He may strengthen your hearts and make your feet firm with it
﴾12﴿ When your Lord revealed to the angels, I am with you, so strengthen those who believe Surely, I will cast terror into the hearts of the disbelievers. Strike them on their necks and strike every knuckle of their fingers

[11] This is the fourth reason, which discusses other forms of divine assistance (nasr-e-Ilahi), and four benefits of the rain are mentioned.
The summary is that in the battlefield of Badr, fear came upon the noble Companions due to their small numbers. Another factor was that Satan cast a whisper in their hearts, saying: “You have no water, and you are on sandy ground—so how will you fight?”
Then Allah the Exalted sent a gentle slumber upon them, through which He removed their fear. And He caused rain to fall, through which purification was attained, and Satan’s whisperings were removed.
"An-nu‘ās" refers to light sleep, which is visible in the nodding of the head.
"Amanah" is a state where the cause of fear still exists, but the fear itself is removed. This is considered a miracle and a divine favor. On the other hand, "amn" is when even the cause of fear is removed.
Here, since the disbelievers were still present and ready for battle, the battle remained—but the fear was removed; hence, the word "amanah" is used. Similarly, in verse 154 of Surah Aal-e-Imran, the same is mentioned. There, it refers to one group—because in the Battle of Uhud, hypocrites were present, and they did not experience this sleep. But in the Battle of Badr, there were no hypocrites, so the address here is to all.
"Li yutahhirakum" (to purify you): refers to purification through wudu (ablution) and ghusl (ritual bath).
"Rijz ash-shaytan": refers to being without wudu, being in a state of janabah (major impurity), or to the satanic whisperings placed in the hearts of believers—like “you have no water, so clearly you are not on the right path.”
"Li yarbiṭa" (to strengthen): Binding the heart (rabṭ al-qalb) is a quality of the friends of Allah (awliya). There is a difference between rabṭ and iṭmi’nan (reassurance): iṭmi’nan comes through remembrance (dhikr), while rabṭ does not rely on any cause—it is firmness of heart in belief, mission, and struggle, without any fear.
"Wa li yarbiṭa" – the use of “lam” (li) shows that it connects to both the sending of slumber and rain.
"Yuthabbit bihi" – the pronoun "bihi" refers either to the heart-strengthening or to the rainwater.
[12] This is the fifth reason for the first claim. The summary is that Allah the Exalted made the angels partners with you in the battle, and through that, the spoils of war were attained—so do not dispute over them.
"Fa-thabbitu alladhina amanu" (So make firm those who have believed): This had three types of affirmations (thabt):
1. Verbal affirmation – meaning: give glad tidings to the believers of the help of Allah the Exalted.
2. Practical affirmation – the angels were present for combat. Some believers saw them in the form of men, and some heard their voices, though they did not recognize them until the Prophet (May Allah bless him and give him peace) informed them.
3. Spiritual affirmation – through divine inspiration in the hearts of the believers.
"Anni ma‘akum" (Indeed, I am with you): this is the final form of divine accompaniment (ma‘iyyat), and it shows that even the angels are in need of Allah’s help in granting victory.
There is also a possible interpretation that the phrase "qulu" (say) is implied: say to the believers on behalf of Allah the Exalted, "Indeed, I am with you."
"Sa’ulqi" (I will cast): This either explains “ma‘akum” (I am with you), or it is the result of "fa-thabbitu" (so make firm).
"Ar-ru‘b" (terror): means the heart becoming filled with fear due to the anticipation of calamity.
"Fawq al-a‘naq" (above the necks): refers to the back portion of the neck, or possibly the entire head.
"Banan" (fingers or fingertips): this is specifically mentioned because striking them can be significant in combat—it disables the opponent’s ability to fight.