Allah(swt), told us to make us realize

 قَدْ كَانَ لَكُمْ آيَةٌ فِي فِئَتَيْنِ الْتَقَتَا فِئَةٌ تُقَاتِلُ فِي سَبِيلِ اللّهِ وَأُخْرَى كَافِرَةٌ يَرَوْنَهُم مِّثْلَيْهِمْ رَأْيَ الْعَيْنِ وَاللّهُ يُؤَيِّدُ بِنَصْرِهِ مَن يَشَاء إِنَّ فِي ذَلِكَ لَعِبْرَةً لَّأُوْلِي الأَبْصَارِ 3:13

(Fathe Muhammad Jalandari)
تمہارے ليے دو گروہوں ميں جو (جنگ بدر کے دن) آپس ميں بھڑ گئے (قدرت خدا کي عظيم الشان) نشاني تھي ايک گروہ (مسلمانوں کا تھا وہ) خدا کي راہ ميں لڑ رہا تھا اور دوسرا گروہ (کافروں کا تھا وہ) ان کو اپني آنکھوں سے اپنے سے دگنا مشاہدہ کر رہا تھا اور خدا اپني نصرت سے جس کو چاہتا ہے مدد ديتا ہے جو اہل بصارت ہيں ان کے ليے اس (واقعے) ميں بڑي عبرت ہے 3:13

(Muhammad Assad)
 3:13 You have already had a sign in the two hosts that met in battle, one host fighting in God's cause and the other denying Him; with their own eyes [the former] saw the others as twice their own number: but God strengthens with His succour whom He wills. In this, behold, there is indeed a lesson for all who have eyes to see. 3:13

(Yousaf Ali)
 3:13 "There has already been for you a Sign in the two armies that met (in combat): One was fighting in the cause of Allah, the other resisting Allah. these saw with their own eyes Twice their number. But Allah doth support with His aid whom He pleaseth. In this is a warning for such as have eyes to see."3:13