Surat Al Anfal: (65-66)

{يَا أَيُّهَا النَّبِيُّ حَرِّضِ الْمُؤْمِنِينَ عَلَى الْقِتَالِ إِن يَكُن مِّنكُمْ عِشْرُونَ صَابِرُونَ يَغْلِبُواْ مِئَتَيْنِ وَإِن يَكُن مِّنكُم مِّئَةٌ يَغْلِبُواْ أَلْفاً مِّنَ الَّذِينَ كَفَرُواْ بِأَنَّهُمْ قَوْمٌ لاَّ يَفْقَهُونَ} [الأنفال : 65]

65- O Prophet, urge the believers to fighting and exhort them to Jihad because if you have twenty fighters who seek the reward from Allah, they shall defeat two hundreds of their enemies. If you have one hundred patient fighters, they shall defeat one thousand of the disbelievers that is because polytheists are ignorant and do not fight for the sake of Allah or for the sake of His Reward, but they fight out of ignorance and following to the steps of Satan, so they do not stand firm in battles if you are truthful.

That matter was difficult for Muslims when each one of them was asked to fight ten fighters of the disbelievers, then the following Ayah was revealed to alleviate the matter and told them that one should confront two of them. Ibn `Abbas (may Allah be pleased with him) said: When Allah (Glory be to Him) alleviated the matter for them, their patience reduced in the same matter.

The majority of scholars said that the second Ayah abrogated the first Ayah.

{الآنَ خَفَّفَ اللّهُ عَنكُمْ وَعَلِمَ أَنَّ فِيكُمْ ضَعْفاً فَإِن يَكُن مِّنكُم مِّئَةٌ صَابِرَةٌ يَغْلِبُواْ مِئَتَيْنِ وَإِن يَكُن مِّنكُمْ أَلْفٌ يَغْلِبُواْ أَلْفَيْنِ بِإِذْنِ اللّهِ وَاللّهُ مَعَ الصَّابِرِينَ} [الأنفال : 66]

66- Now, Allah alleviated the previous ruling and knew that you are weak to fight ten fighters, so if you only have one hundred patient fighters, they shall defeat two hundred of the disbelievers and if you have one thousand, they shall defeat two thousands, so one should fight two. Therefore, if the Muslim army half the number of the disbeliever's army, they shall defeat them by the will of Allah, for Allah provides victory to the patient, so how could not they defeat their enemy?