Ibn ‘Abbās (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) on the day (of the battle) of Badr, said: "This is Jibrīl holding the head of his horse and equipped with tools of war."
This Hadīth is about the participation of angels, headed by Jibrīl (peace be upon him) in the battle of Badr. The Prophet (may Allah's peace and blessings be upon him) informed that he saw Jibrīl mounting his horse in the battle of Badr, while equipped with tools of war to fight alongside the believers, to support and consolidate the Prophet (may Allah's peace and blessings be upon him) and to back his Companions.