Surah Ali 'Imran 3:123

وَلَقَدْ نَصَرَكُمُ ٱللَّهُ بِبَدْرٍ وَأَنتُمْ أَذِلَّةٌ ۖ فَٱتَّقُوا۟ ٱللَّهَ لَعَلَّكُمْ تَشْكُرُونَ

And already had Allāh given you victory at [the battle of] Badr while you were weak [i.e., few in number]. Then fear Allāh; perhaps you will be grateful.

Translation: Saheeh International

Tafsir

When they were defeated the following was revealed as a way of reminding them of God’s favour God already gave you victory at Badr a location between Mecca and Medina when you were contemptible few in number and weapons. So fear God in order that you might be thankful for His blessings.

Excerpt from Tafsir al-Jalalayn, commentary on 3:123, via Quran.com. The reader has the full commentary and 9 more tafsirs.