This was a command from Him to His servant—peace be upon him—to gird his loins for Death in the matter He commanded him to perform.1
This is supported by the words of our sheikh al-Khasibi—may God ennoble his station—in his Lami-poem:
Death is higher than killing, and the discourse is lengthy.
"The Meaning is Death and the Name is Killing." The Arabs named our Master—exalted be His mention—by this name due to what they witnessed of His great might on the Day of Badr. It was related that after that day, if a man met another and asked, "Where do you intend to go?" he would reply, "I wish to go to the Orphan of Abu Talib"—meaning our lord the Messenger, exalted be his glory—"to debate and outshine him."
The other would say to him: "Turn back from your destination, for Death walks when the Orphan of Abu Talib walks and stands when he stands." On the Day of Uhud, everyone who had seen Him on the Day of Badr avoided Him, turning to flee; while he who had not seen Him wished he had. Then God the Sublime sent down to His Messenger—exalted be his glory: {And you had certainly been wishing for death before you met it, and you have [now] seen it while you were looking on}.2
He was named on the Day of Badr: al-Sim'am' (The Bold/The Wolf)
(281) This is what we related by its chain of transmission—which we omitted for the sake of brevity—from Mus’ab ibn Sa’d, from his father Sa’d ibn Abi Waqqas, who said: Uthman said to me, "Do you love Ali?" I replied, "Yes; how could I not love him when I heard the Messenger of God—exalted be his glory—saying to him: 'You are to me as Aaron was to Moses, except there is no prophet after me'?"