ثُمَّ اَنْزَلَ عَلَيْكُمْ مِّنْۢ بَعْدِ الْغَمِّ اَمَنَةً نُّعَاسًا يَّغْشٰى طَۤاىِٕفَةً مِّنْكُمْ ۙ وَطَۤاىِٕفَةٌ قَدْ اَهَمَّتْهُمْ اَنْفُسُهُمْ يَظُنُّوْنَ بِاللّٰهِ غَيْرَ الْحَقِّ ظَنَّ الْجَاهِلِيَّةِ ۗ يَقُوْلُوْنَ هَلْ لَّنَا مِنَ الْاَمْرِ مِنْ شَيْءٍ ۗ قُلْ اِنَّ الْاَمْرَ كُلَّهٗ لِلّٰهِ ۗ يُخْفُوْنَ فِيْٓ اَنْفُسِهِمْ مَّا لَا يُبْدُوْنَ لَكَ ۗ يَقُوْلُوْنَ لَوْ كَانَ لَنَا مِنَ الْاَمْرِ شَيْءٌ مَّا قُتِلْنَا هٰهُنَا ۗ قُلْ لَّوْ كُنْتُمْ فِيْ بُيُوْتِكُمْ لَبَرَزَ الَّذِيْنَ كُتِبَ عَلَيْهِمُ الْقَتْلُ اِلٰى مَضَاجِعِهِمْ ۚ وَلِيَبْتَلِيَ اللّٰهُ مَا فِيْ صُدُوْرِكُمْ وَلِيُمَحِّصَ مَا فِيْ قُلُوْبِكُمْ ۗ وَاللّٰهُ عَلِيْمٌ ۢبِذَاتِ الصُّدُوْرِ ( آل عمران: ١٥٤ )
Summa anzala 'alaikum mim ba'dil ghammi amanatan nu'aasai yaghshaa taaa' ifatam minkum wa taaa'ifatun qad ahammathum anfusuhum yazunnoona billaahi ghairal haqqi zannal jaahiliyyati yaqooloona hal lanaa minal amri min shai'; qul innal amra kullahoo lillaah; yukhfoona fee anfusihim maa laa yubdoona laka yaqooloona law kaana lanaa minal amri shai'ummaa qutilnaa haahunaa; qul law kuntum fee buyootikum labarazal lazeena kutiba 'alaihimul qatlu ilaa madaaji'ihim wa liyabtaliyal laahu maa fee sudoorikum wa liyumah hisa maa fee quloobikum; wallaahu 'aleemum bizaatis sudoor (ʾĀl ʿImrān 3:154)
Sahih International:
Then after distress, He sent down upon you security [in the form of] drowsiness, overcoming a faction of you, while another faction worried about themselves, thinking of Allah other than the truth – the thought of ignorance, saying, "Is there anything for us [to have done] in this matter?" Say, "Indeed, the matter belongs completely to Allah." They conceal within themselves what they will not reveal to you. They say, "If there was anything we could have done in the matter, we [i.e., some of us] would not have been killed right here." Say, "Even if you had been inside your houses, those decreed to be killed would have come out to their death beds." [It was] so that Allah might test what is in your breasts and purify what is in your hearts. And Allah is Knowing of that within the breasts. (Ali 'Imran [3] : 154)
1 Mufti Taqi Usmani
Then, after the grief, He poured tranquility upon you - a drowsiness overtaking a group of you. Another group was worrying about their own selves, harboring thoughts about Allah that were untrue - thoughts of ignorance. They were saying, “Is there anything in our hands?” Say, “The whole thing belongs to Allah.” They conceal in their hearts what they do not disclose to you.They say, “If we had any say in the matter, we would not have been killed here.”Say, “If you were in your homes, those destined to be killed would have come out all the way to their (final) resting -places.” (All this was done) so that Allah may test your inner qualities and may purify what is in your hearts. Allah is All-Aware of what lies in the hearts.