In Deuteronomy 8:3 why is "live" a future verb?

Question

[Deu 8:3 ASV] (3) And he humbled thee, and suffered thee to hunger, and fed thee with manna, which thou knewest not, neither did thy fathers know; that he might make thee know that man doth not live by bread only, but by everything that proceedeth out of the mouth of Jehovah doth man live.

[Deu 8:3 mGNT] (3) καὶ ἐκάκωσέν σε καὶ ἐλιμαγχόνησέν σε καὶ ἐψώμισέν σε τὸ μαννα ὃ οὐκ εἴδησαν οἱ πατέρες σου ἵνα ἀναγγείλῃ σοι ὅτι οὐκ ἐπ᾽ ἄρτῳ μόνῳ ζήσεται ὁ ἄνθρωπος ἀλλ᾽ ἐπὶ παντὶ ῥήματι τῷ ἐκπορευομένῳ διὰ στόματος θεοῦ ζήσεται ὁ ἄνθρωπος

I'm not sure what the Hebrew is doing because I don't know Hebrew at all:

Masoretic Deuteronomy 8:3 וַֽיְעַנְּךָ וַיַּרְעִבֶךָ וַיַּֽאֲכִֽלְךָ אֶת־הַמָּן אֲשֶׁר לֹא־יָדַעְתָּ וְלֹא יָדְעוּן אֲבֹתֶיךָ לְמַעַן הֹודִֽעֲךָ כִּי לֹא עַל־הַלֶּחֶם לְבַדֹּו יִחְיֶה הָֽאָדָם כִּי עַל־כָּל־מֹוצָא פִֽי־יְהוָה יִחְיֶה הָאָדָֽם׃

Matthew follows suit with Deuteronomy LXX:

[Mat 4:4 ASV] (4) But he answered and said, It is written, Man shall not live by bread alone, but by every word that proceedeth out of the mouth of God.

[Mat 4:4 MGNT] (4) ὁ δὲ ἀποκριθεὶς εἶπεν γέγραπται οὐκ ἐπ’ ἄρτῳ μόνῳ ζήσεται ὁ ἄνθρωπος ἀλλ’ ἐπὶ παντὶ ῥήματι ἐκπορευομένῳ διὰ στόματος θεοῦ

Does whatever the Hebrew word is have a future, gnomic or an imperative sense?

Note:

I got this question from here: https://vimeo.com/348872750

Answer 1

The usage is gnomic, that is, a general truth (to use the expression of the linked video). It's clearly not predictive—why would Jesus invoke something not yet true as proof of His behavior in the present! It's clearly not Imperative: as if man should abstain from eating bread all his life and starve to death. It's not Deliberative because of the absence of any interrogatory parts of speech in either the Greek or Hebrew.

The book in the linked video seems to commit a fallacy of 'its use in the other quotations by Jesus is imperative therefore they must all be'—it simply doesn't follow.

It's also disproven by the simplest look at the context of the passage (translated from the Hebrew):

And he humbled you, and allowed you to go hungry, and fed you with manna, which neither you for your fathers knew, so that you might know that a man does not live by bread alone, but that a man lives by every word proceeding from the mouth of the Lord.

Which is clearly gnomic.

The Hebrew or Aramaic we can be certain Christ used makes no audible or lexical distinction in verb forms for the simple future, 'gnomic' etc. here, just like the Greek, whereas they are to be distinguished by context.