Proverbs 30:5 → Deuteronomy 4:2

Proverbs 30:5 declares "every word of God is flawless" (כָּל־אִמְרַת אֱלוֹהַּ צְרוּפָה, kol-imrat eloah tseruphah), using metallurgical imagery of refining to assert the purity of divine speech. This provides the theological ground for the prohibition in Deuteronomy 4:2, "You must not add to (לֹא תֹסִפוּ, lo tosifu) or subtract from what I command you" -- if God's word is already perfectly refined, any human addition would contaminate it. Agur's declaration functions as a wisdom tradition affirmation of the Mosaic principle: because God's words are tested and proven reliable, they serve as a shield (מָגֵן, magen) to those who trust them, making supplementation both unnecessary and dangerous. To add would not merely contaminate the word but implicitly accuse God Himself of leaving His revelation incomplete.