قَدْ كَانَ لَكُمْ ءَايَةٌ فِى فِئَتَيْنِ ٱلْتَقَتَا ۖ فِئَةٌ تُقَـٰتِلُ فِى سَبِيلِ ٱللَّهِ وَأُخْرَىٰ كَافِرَةٌ يَرَوْنَهُم مِّثْلَيْهِمْ رَأْىَ ٱلْعَيْنِ ۚ وَٱللَّهُ يُؤَيِّدُ بِنَصْرِهِۦ مَن يَشَآءُ ۗ إِنَّ فِى ذَٰلِكَ لَعِبْرَةً لِّأُو۟لِى ٱلْأَبْصَـٰرِ
qad kāna lakum āyatun fī fi-atayni l-taqatā fi-atun tuqātilu fī sabīli l-lahi wa-ukh'rā kāfiratun yarawnahum mith'layhim raya l-ʿayni wal-lahu yu-ayyidu binaṣrihi man yashāu inna fī dhālika laʿib'ratan li-ulī l-abṣāri
You have already seen a sign in the two armies that met in battle, one fighting for God’s cause and the other made up of disbelievers. With their own eyes [the former] saw [the latter] to be twice their number, but God helps whoever He will. There truly is a lesson in this for all with eyes to see.’
There has already been a sign for you (O Jews) in the two armies that met (in combat i.e. the battle of Badr). One was fighting in the Cause of Allâh, and as for the other, (they) were disbelievers. They (the believers) saw them (the disbelievers) with their own eyes twice their number (although they were thrice their number). And Allâh supports with His Victory whom He wills. Verily, in this is a lesson for those who understand. (See Verse 8:44). (Tafsir At-Tabarî)