Surah Al-Anfal 8:43

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

[Remember, O Muḥammad], when Allāh 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 Allāh saved [you from that]. Indeed, He is Knowing of that within the breasts.

Translation: Saheeh International

Tafsir

Remember when God showed them to you in your dream in your sleep as few and so you informed your companions of this and they were delighted and had He shown them to you as many you would have faltered shrunk in cowardice and quarrelled fallen into disagreement over the matter the matter of fighting; …

Excerpt from Tafsir al-Jalalayn, commentary on 8:43, via Quran.com. The reader has the full commentary and 9 more tafsirs.