Le Deutéronome 13:4 Commentaire : Chizkuni, Ramban, Ibn Ezra & Sforno

לא תשמע אל דברי הניא ההוא, “do not listen to the words of that “prophet;” it is illogical to believe that such a prophet’s miracle could override My commandments to you, seeing that I have warned you of the possibility of such false prophets arising already before any such person did in fact claim to be My prophet.

FOR THE ETERNAL YOUR G-D TRIETH YOU. This is to state that the purport of the wonder which came to pass and which G-d showed him in his dream or [as the philosophers say] in his kahin¹⁰⁷This is borrowed from the Arabic, kahanah, a term referring to the power residing in man to be able to foretell the future. It is so explained by Shmuel ibn Tibbon in his list of “Foreign words.” was G-d’s will in order to test you in your love of Him. Now I have already explained¹³⁸Genesis 2:1 (Vol. I, p. 275). that the term “test” is derived from the point of view of the one who is being tested. It states here to know [for the Eternal your G-d trieth you ‘to know’ whether ye do love … meaning] that it became known in fact what exists in potential and is revealed [only] to Him. Thus the commandment of this entire section refers to someone who prophesies to worship the idols. But concerning one who prophesies in the name of G-d to change any of the commandments of the Torah, our Rabbis have interpreted¹³¹Sanhedrin 90a. that if he came to [completely] uproot any item from the Torah, such as permitting [the eating of] swine or [permitting] one of the adulterous relationships, according to this judgment shall it be done to him¹³⁹Exodus 21:31. [i.e., he is liable to death as is stated here in Verse 6]. But if he declares it to be permissible only for some time as a temporary measure such as Elijah did on Mount Carmel [in permitting offerings to G-d outside of the Sanctuary in Jerusalem],¹⁴⁰I Kings 18:33-38. The purpose was to vindicate the belief in the true G-d and cause the people to reject the idolatrous worship of Baal. And because Elijah was an acknowledged righteous prophet we were commanded to listen to him (Rambam, Hilchoth Yesodei Hatorah 9:3). we are obligated to listen to him and to do everything that he commands us.
It appears [to me] that if he prophesies in the name of G-d to command a precept that he innovates, as happened concerning reading of the Scroll [of Esther on Purim],¹⁴¹See Ramban above, 4:2. that he is not guilty of a capital offense, only that we are not to obey him, because it is written, These are the commandments,¹⁴²Leviticus 27:34. [which our Rabbis interpret to mean]:¹⁴³Torath Kohanim, end of Bechukothai. The reading of the Megillah (Scroll of Esther) on Purim is “a positive commandment by the authority of the Scribes” (Mishneh Torah, Hilchoth Megillah V’Chanukah 1:1). “No prophet is henceforth permitted to declare any new matter therein.” But perhaps, since we do not believe him, he is thus a false prophet and his death is by strangulation.¹⁴⁴See “The Commandments,” Vol. II, pp. 25-26.

test in that He let him be, and did not kill him. God tests people to reveal the virtue of him who is tested.