Abu al-Yasar killed Abu al-Bukhtari, while most people insist that al-Mujadhdhar was the one who slew him; in truth, the fatal blow was dealt by Abu Dawud al-Mazani.
He relates: Ibn Masʿud found Abu Jahl lying fallen not far from the battlefield, fully encased in mail, his sword resting across his thighs. He bore not a single wound, yet he could not move a limb and lay face-down, staring at the ground. Ibn Masʿud circled around him, intending to finish him off but afraid the man might suddenly rise. When he saw that Abu Jahl remained motionless, supposing him pinned down by injury, he wanted to strike him with his own sword but feared it would not suffice. Coming up from behind, he grasped the hilt of Abu Jahl’s sword, drew it while the man was still prone, lifted the back of his helmet’s mail, and struck him; his head fell before him, and Ibn Masʿud stripped him of his arms.
On closer inspection he saw no wounds, only bruises on Abu Jahl’s neck, hands, and shoulders that looked like the marks of lashes. He went to the Messenger of Allah ﷺ and informed him. The Prophet ﷺ said, “That was the striking of the angels.”
He continues: Through the victory at Badr Allah humbled the idolaters and the hypocrites; in Medina not a single hypocrite or Jew remained without bowing his neck in submission to the outcome of Badr. That was the Day of Distinction—the day on which Allah separated disbelief from faith.
The Jews said, “We are now certain that he is the Prophet whose description we find in the Torah. By Allah, no banner will henceforth be raised against him without being routed.”
The people of Mecca mourned their dead for an entire month.
The Prophet ﷺ then returned to Medina, entering it by the Pass of al-Wadaʿ.
Thereafter the Quran was revealed, and Allah made them recognize His favor in what they had at first disliked—the Prophet’s going out to Badr—saying: “Just as your Lord brought you out of your home with the truth, though a party of the believers were unwilling” (Al-Anfal 5), along with three other verses.