Qur'an 8:43

إِذْ يُرِيكَهُمُ ٱللَّهُ فِى مَنَامِكَ قَلِيلًا ۖ وَلَوْ أَرَىٰكَهُمْ كَثِيرًا لَّفَشِلْتُمْ وَلَتَنَـٰزَعْتُمْ فِى ٱلْأَمْرِ وَلَـٰكِنَّ ٱللَّهَ سَلَّمَ ۗ إِنَّهُۥ عَلِيمٌۢ بِذَاتِ ٱلصُّدُورِ

When Allah showed them unto thee (O Muhammad) in thy dream as few in number, and if He had shown them to thee as many, ye (Muslims) would have faltered and would have quarreled over the affair. But Allah saved (you). Lo! He knoweth what is in the breasts (of men).