Sura al-Nisāʾ 4:102

وَإِذَا كُنتَ فِيهِمْ فَأَقَمْتَ لَهُمُ ٱلصَّلَوٰةَ فَلْتَقُمْ طَآئِفَةٌ مِّنْهُم مَّعَكَ وَلْيَأْخُذُوٓا۟ أَسْلِحَتَهُمْ فَإِذَا سَجَدُوا۟ فَلْيَكُونُوا۟ مِن وَرَآئِكُمْ وَلْتَأْتِ طَآئِفَةٌ أُخْرَىٰ لَمْ يُصَلُّوا۟ فَلْيُصَلُّوا۟ مَعَكَ وَلْيَأْخُذُوا۟ حِذْرَهُمْ وَأَسْلِحَتَهُمْ وَدَّ ٱلَّذِينَ كَفَرُوا۟ لَوْ تَغْفُلُونَ عَنْ أَسْلِحَتِكُمْ وَأَمْتِعَتِكُمْ فَيَمِيلُونَ عَلَيْكُم مَّيْلَةً وَٰحِدَةً وَلَا جُنَاحَ عَلَيْكُمْ إِن كَانَ بِكُمْ أَذًى مِّن مَّطَرٍ أَوْ كُنتُم مَّرْضَىٰٓ أَن تَضَعُوٓا۟ أَسْلِحَتَكُمْ وَخُذُوا۟ حِذْرَكُمْ إِنَّ ٱللَّـهَ أَعَدَّ لِلْكَٰفِرِينَ عَذَابًا مُّهِينًا

wa-idhā kunta fīhim fa-aqamta lahumu l-ṣalāta faltaqum ṭāʾifatun minhum maʿaka wa-lyakhudhū asliḥatahum fa-idhā sajadū falyakūnū min warāikum wa-ltati ṭāʾifatun ukhrā lam yuṣallū fa-lyuṣallū maʿaka wa-lyakhudhū ḥidhrahum waasliḥatahum wadda lladhīna kafarū law taghfulūna ʿan asliḥatikum wa-amtiʿatikum fa-yamīlūna ʿalaykum maylatan wāḥidatan wa-lā junāḥa ʿalaykum in kāna bikum adhan min maṭarin aw kuntum marḍā an taḍaʿū asliḥatakum wa-khudhū ḥidhrakum inna allāha aʿadda lil-kāfirīna ʿadhāban muhīnan

When thou (O Messenger) art with them, and standest to lead them in prayer, Let one party of them stand up (in prayer) with thee, Taking their arms with them: When they finish their prostrations, let them Take their position in the rear. And let the other party come up which hath not yet prayed - and let them pray with thee, Taking all precaution, and bearing arms: the Unbelievers wish, if ye were negligent of your arms and your baggage, to assault you in a single rush. But there is no blame on you if ye put away your arms because of the inconvenience of rain or because ye are ill; but take (every) precaution for yourselves. For the Unbelievers Allah hath prepared a humiliating punishment.