Surah Al-Anfal · Ayah 43

إِذْ يُرِيكَهُمُ ٱللَّهُ فِى مَنَامِكَ قَلِيلًۭا ۖ وَلَوْ أَرَىٰكَهُمْ كَثِيرًۭا لَّفَشِلْتُمْ وَلَتَنَٰزَعْتُمْ فِى ٱلْأَمْرِ وَلَٰكِنَّ ٱللَّهَ سَلَّمَ ۗ إِنَّهُۥ عَلِيمٌۢ بِذَاتِ ٱلصُّدُورِ

Iz yureekahumul laahu fee manaamika qaleela; wa law araakahum kaseeral lafashiltum wa latanaaza'tum fil amri wa laakinnal laaha sallam; innahoo 'aleemum bizaatis sudoor

[Remember, O Muhammad], when Allah showed them to you in your dream as few; and if He had shown them to you as many, you [believers] would have lost courage and would have disputed in the matter [of whether to fight], but Allah saved [you from that]. Indeed, He is Knowing of that within the breasts.