At-Taubah - 9:40

إِلاَّ تَنصُرُوهُ فَقَدْ نَصَرَهُ اللّهُ إِذْ أَخْرَجَهُ الَّذِينَ كَفَرُواْ ثَانِيَ اثْنَيْنِ إِذْ هُمَا فِي الْغَارِ إِذْ يَقُولُ لِصَاحِبِهِ لاَ تَحْزَنْ إِنَّ اللّهَ مَعَنَا فَأَنزَلَ اللّهُ سَكِينَتَهُ عَلَيْهِ وَأَيَّدَهُ بِجُنُودٍ لَّمْ تَرَوْهَا وَجَعَلَ كَلِمَةَ الَّذِينَ كَفَرُواْ السُّفْلَى وَكَلِمَةُ اللّهِ هِيَ الْعُلْيَا وَاللّهُ عَزِيزٌ حَكِيمٌ
[9:40]
If you will not aid him, Allah certainly aided him when those who disbelieved expelled him, he being the second of the two, when they were both in the cave, when he said to his companion: Grieve not, surely Allah is with us. So Allah sent down His tranquillity upon him and strengthened him with hosts which you did not see, and made lowest the word of those who disbelieved; and the word of Allah, that is the highest; and Allah is Mighty, Wise.
If ye help not (your leader), (it is no matter): for Allah did indeed help him, when the Unbelievers drove him out: he had no more than one companion; they two were in the cave, and he said to his companion, "Have no fear, for Allah is with us": then Allah sent down His peace upon him, and strengthened him with forces which ye saw not, and humbled to the depths the word of the Unbelievers. But the word of Allah is exalted to the heights: for Allah is Exalted in might, Wise.
If ye help him not, still Allah helped him when those who disbelieve drove him forth, the second of two; when they two were in the cave, when he said unto his comrade: Grieve not. Lo! Allah is with us. Then Allah caused His peace of reassurance to descend upon him and supported him with hosts ye cannot see, and made the word of those who disbelieved the nethermost, while Allah's Word it was that became the uppermost. Allah is Mighty, Wise.