“O Messenger, let not those who rush headlong into unbelief grieve you—those who say with their mouths, ‘We believe,’ while their hearts do not believe; and among the Jews are people who eagerly listen to falsehood, listening on behalf of others who have never come to you. They distort words after they have been properly placed, saying, ‘If you are given this ruling, accept it; but if you are not given it, then beware.’ Whomever Allah wills to test, you can in no way help against Allah. Such are the ones whose hearts Allah does not wish to purify; for them is disgrace in this world, and in the Hereafter a mighty punishment. They are avid listeners to lies and voracious consumers of illicit gain. If they come to you, judge between them or turn away from them. Should you turn away, they will not harm you in the least; but if you judge, then judge between them with equity—for Allah loves those who act justly.
How is it that they seek you to judge while they have the Torah, in which is Allah’s judgment? Yet after that they turn away, and those people are not believers. Indeed, We sent down the Torah, containing guidance and light. By it the prophets who had submitted judged for the Jews, as did the rabbis and scholars, for they had been entrusted with the Book of Allah and were witnesses to it. So do not fear the people, but fear Me, and do not barter My revelations for a paltry price. Whoever does not judge by what Allah has sent down—it is they who are the disbelievers. And We prescribed for them therein: life for life, eye for eye, nose for nose, ear for ear, tooth for tooth, and for wounds equitable retaliation. But whoever forgoes it, that is an expiation for him. Whoever does not judge by what Allah has sent down—it is they who are the wrongdoers. And We caused Jesus son of Mary to follow in their footsteps, confirming what was before him of the Torah, and We gave him the Gospel.” [al-Maʾida: 41–46]
Thus it is explicit that the Jews who brought their case before the Prophet—may Allah bless him and grant him peace—already possessed the Torah, within which lay Allah’s ruling, yet they turned away from Allah’s judgment. Immediately thereafter He said: “And let the people of the Gospel judge by what Allah has revealed therein” [al-Maʾida: 47].
The prefixed lām here is the lām of command: it is a divine injunction revealed through the tongue of Muhammad. A command cannot apply to those who had died before this address; it can only be directed to those who were alive and had believed.