Musnad Ahmad 32:286

Yazid narrated to us, Hammam informed us, from Qatadah, from Anas, who said: When the Messenger of Allah (peace and blessings of Allah be upon him) returned from al-Hudaybiyah, this verse was revealed: "Indeed, We have given you a clear conquest, that Allah may forgive for you what preceded of your sin and what will follow and complete His favor upon you and guide you to a straight path." [Al-Fath: 1-2] The Muslims said: "O Messenger of Allah, congratulations to you for what Allah has given you, but what is for us?" Then it was revealed: "That He may admit the believing men and the believing women to gardens beneath which rivers flow to abide therein eternally and remove from them their misdeeds - and ever is that, in the sight of Allah, a great attainment." [Al-Fath: 5]