Psalms 2:9 - Joseph Benson’s Commentary on the Old and New Testaments

Thou shalt break them with a rod of iron Those people that will not quietly submit to thee shall be crushed and destroyed by thy mighty power, which they shall never be able to resist. This was in part fulfilled when the Jews, who persisted in unbelief, were destroyed by the Roman power: and in the destruction of the pagan power when the Christian religion came to be established. But it will not be completely fulfilled till all opposing power and principality be put down.