Surah al-Nasr (Divine Help) is Meccan (1).
In the Name of Allah, the Most Compassionate, the Most Merciful.
“When Allah’s help and victory come (1).”
“Whenever Allah’s help and victory come” refers to the conquest of Mecca.
Its account—as related by Muhammad ibn Ishaq and the historians—is that when the Messenger of Allah, may Allah bless him and grant him peace, concluded a truce with Quraysh in the year of al-Hudaybiyyah, they agreed to suspend warfare among the people for ten years, during which people would be safe and refrain from fighting one another. They further agreed that whoever wished to enter into the covenant and alliance of the Messenger of Allah, may Allah bless him and grant him peace, could do so, and whoever wished to enter into the covenant and alliance of Quraysh could do so. Thus, Banu Bakr entered into the alliance of Quraysh, while Khuza'ah entered into the covenant of the Messenger of Allah, may Allah bless him and grant him peace. There had long been enmity between the two.
Then Banu Bakr attacked Khuza'ah while they were at one of their watering places in the lower part of Mecca, called al-Watir. Nawfal ibn Mu'awiyah al-Du'ali set out with Banu al-Du'il, a branch of Banu Bakr, and launched a night raid against Khuza'ah; not all of Banu Bakr followed him. They struck down one of them, and fighting broke out between the two sides. Quraysh supplied Banu Bakr with weapons, and some men of Quraysh fought alongside them secretly at night, until they drove Khuza'ah into the Sacred Precinct.
Among those from Quraysh who personally aided Banu Bakr against Khuza'ah that night, disguising themselves, were Safwan ibn Umayyah, Ikrimah ibn Abi Jahl, and Suhayl ibn Amr, together with their slaves. When they reached the Sacred Precinct, Banu Bakr said, “O Nawfal, we have entered the Sacred Precinct! Your god, your god!” But he uttered a terrible statement: “Today I have no god. [O Banu Bakr] (2), take your revenge within it.”