8:66Al-Anfaal

When the Verse:--'If there are twenty steadfast amongst you (Muslims), they will overcome twohundred (non-Muslims).' was revealed, it became hard on the Muslims when it became compulsory that one Muslim ought not to flee (in war) before ten (non-Muslims). So (Allah) lightened the order by revealing: '(But) now Allah has lightened your (task) for He knows that there is weakness in you. So if there are of you one-hundred steadfast, they will overcome (two-hundred (non-Muslims).' (8.66) So when Allah reduced the number of enemies which Muslims should withstand, their patience and perseverance against the enemy decreased as much as their task was lightened for them.

Ibn ‘Abbas said “When the verse “If there are twenty amongst you patient and persevering, they will vanquish two hundred” was revealed. It was heavy and troublesome for Muslims when Allaah prescribed for them that one (fighting Muslim) should not fly from ten (fighting Non-Muslims). Then a light commandment was revealed saying “For the present Allaah hath lightened your (task).” The narrator Abu Tawbah recited the verse to “they will vanquish two hundred.” When Allaah lightened the number, patient and perseverance also decreased according to the number lightened from them.”

When the Verse:-- "If there are twenty steadfast amongst you, they will overcome two hundred." (8.65) was revealed, then it became obligatory for the Muslims that one (Muslim) should not flee from ten (non-Muslims). Sufyan (the sub-narrator) once said, "Twenty (Muslims) should not flee before two hundred (non Muslims)." Then there was revealed: 'But now Allah has lightened your (task)..' (8.66) So it became obligatory that one-hundred (Muslims) should not flee before two hundred (nonmuslims). (Once Sufyan said extra, "The Verse: 'Urge the believers to the fight. If there are twenty steadfast amongst you (Muslims) ..' was revealed.) Sufyan said, "Ibn Shabrama said, "I see that this order is applicable to the obligation of enjoining good and forbidding evil."

We were in the company of the Messenger of Allah (ﷺ) when he said. Count for me those who profess al-Islam. We said: Messenger of Allah, do you entertain any fear concerning us and we are (at this time) between six hundred and seven hundred (in strength). He (the Holy Prophet) remarked: You don't perceive; you may be put to some trial, He (the narrator) said: We actually suffered trial so much so that some of our men were constrained to offer their prayers in concealment.

from 'Umar bin Al-Khattab, who said: "The Prophet (ﷺ) looked over the idolaters, and there were a thousand of them, while his Companions were three-hundred and ten and some odd number of men. So the Prophet of Allah (ﷺ) faced the Qiblah, stretched forth his hands and began beseeching his Lord: 'O Allah! Fulfill what You promised for me. O Allah! If you destroy this band of adherents to Islam, you will not be worshiped upon the earth,' He continued beseeching his Lord with his hands stretched, facing the Qiblah until his Rida fell from his shoulders. Abu Bakr came to him, took his Rida and placed it back upon his shoulders, then embraced him from behind and said: 'O Prophet of Allah! You have sufficiently beseeched your Lord, indeed He shall fulfill what He promised you.' So Allah, Blessed and Most High, revealed: When you sought help of your Lord and He answered you (saying): 'I will help you with a thousand of the angels in succession (8:9).' This Hadith is Hasan Sahih Gharib. We do not know of it as a Hadith of 'Umar, except through the narration of 'Ikrimah bin 'Ammar, from Abu Zumail, and Abu Zumail's name is Simãk Al-Hanafi. And this was on the Day of Badr.