Sahih Bukhari Volume 4, Book 52, Hadith Number 164.

Narated By Ibn ‘Abbas : The Prophet , while in a tent (on the day of the battle of Badr) said, “O Allah! I ask you the fulfillment of Your Covenant and Promise. O Allah! If You wish (to destroy the believers) You will never be worshipped after today.” Abu Bakr caught him by the hand and said, “This is sufficient, O Allah’s Apostle! You have asked Allah pressingly.” The Prophet was clad in his armor at that time. He went out, saying to me: “There multitude will be put to flight and they will show their backs. Nay, but the Hour is their appointed time (for their full recompense) and that Hour will be more grievous and more bitter (than their worldly failure).” (54.45-46) Khalid said that was on the day of the battle of Badr.