The prayer reportedly recited by our Prophet (peace and blessings be upon him) in the Battle of Badr…
Hazrat Omar -may Allah be pleased with him- narrates:
THE PRAYER RECITED BY OUR PROPHET AT BADR
On the day of Badr, when the Messenger of Allah –peace and blessings be upon him– looked at the polytheist army he was facing, he saw that their number was a thousand. He then saw that his companions were three hundred and thirteen.[1] He immediately turned towards the qibla (direction of prayer), raised his hands to the sky, and began to earnestly supplicate to his Lord:
“O Allah! Fulfill Your promise to me. O Allah! Grant us victory in this battle. O Allah! If You destroy this community of Muslims, there will be no one left on earth to worship You!”
While continuing his supplications with his hands outstretched, his cloak fell from his shoulder. Seeing this, Abu Bakr –may Allah be pleased with him– approached him, picked up the cloak from the ground, placed it back on his shoulder, and then drew near and said:
“O Messenger of Allah! Your supplication to your Lord is sufficient. Almighty Allah will surely fulfill His promise to you.”
At that time, the Most High and Majestic Allah revealed (sent down) the following noble verse:
“Remember when you asked your Lord for help, and He answered you: ‘Indeed, I will reinforce you with a thousand of the angels following one after another.’” (Surah Al-Anfal, 8:9)
The Almighty assisted the believers with His angels that day.” (Muslim, Jihad, 58; Bukhari, Maghazi, 4)
Footnote:
[1] See Bukhari, Maghazi, 6; Tirmidhi, Siyar, 38/1598.