3 In the mouth of the foolish is a rod of pride: but the lips of the wise shall preserve them.
4 But with righteousness shall he judge the poor, and reprove with equity for the meek of the earth: and he shall smite the earth with the rod of his mouth, and with the breath of his lips shall he slay the wicked.
talks about a rod of iron that is the word of God. That is further evidence that rod in the scriptures means the word of God. Likely prophets in Old Testament times were taught of the tree of life and the rod of iron that guides people to it.
5 And she brought forth a man child, who was to rule all nations with a rod of iron: and her child was caught up unto God, and to his throne.
15 And out of his mouth goeth a sharp sword, that with it he should smite the nations: and he shall rule them with a rod of iron: and he treadeth the winepress of the fierceness and wrath of Almighty God.