The word is אֲנִי (ani), the Hebrew first-person pronoun — “I.” Like its Greek cousin, it’s a small word that can carry a great deal of insistence. Hebrew, like Greek, often folds the subject into the verb, so spelling out ani puts emphasis on the speaker: not just “I am he” but “I am he.” And in the second half of Isaiah — chapters 40 through 55, the soaring monotheistic poetry where the God of Israel stands against all the idols of Babylon — ani becomes the insistent drumbeat of God’s exclusive claim.

Listen for the pattern. Again and again the LORD says אֲנִי הוּא (ani hu), literally “I — he,” which English renders “I am he.” “I, the LORD, the first, and with the last; I am he.” “That you may know and believe me and understand that I am he. Before me no god was formed, nor shall there be any after me.” It recurs in Isaiah 46, in 48, at the high points of the prophet’s vision of salvation. The ani is the front edge of the formula — the self placed forward, named, set against every rival god who is nothing. The “I” insists. It’s God identifying himself by pointing at himself: I am the one, I alone, there is no other beside me.

That insistent “I” is what makes ani hu one of God’s most direct self-naming formulas in the Hebrew Bible — the recognition-line by which the one true God declares his uniqueness. And it matters that the emphasis sits in the pronoun. The whole rhetorical force of these passages is exclusion: every idol is silent, every false god can’t speak or save, and over against them stands the LORD saying ani — I, and not them. The pronoun does the work of monotheism. It draws the line between the God who is and the gods who aren’t.

This is the deep current that runs underneath the Greek of John’s Gospel. When Isaiah was translated into the Septuagint, ani hu — that emphatic Hebrew “I am he” — was rendered with the absolute ἐγὼ εἰμί (egō eimi), the Greek pronoun egō carrying the same forward-pointing insistence as the Hebrew ani. So the loaded weight that a first-century Greek-speaking Jew heard in a bare egō eimi traces straight back to this Hebrew “I”: the LORD of Isaiah declaring himself with the insistent self-naming “I.” Both books anchor the divine-name reading of John 8:58 here — not in the burning bush, where the wording differs, but in Isaiah’s ani hu, which matches exactly.

What the first audience heard in ani was the sound of God refusing to share the name. The insistent Hebrew “I,” repeated across Isaiah’s poems, was the LORD pressing his unique claim — I am he, and no one else is — the self-declaration that would one day echo, in Greek, in a temple courtyard.