Albert Barnes Commentary Psalms 81:15

"The haters of Jehovah should submit themselves unto him: But their time should endure for ever." — Psalms 81:15 (ASV)

The haters of the Lord – The enemies of the Lord, often represented as those who hate him – hatred being always in fact or in form connected with an unwillingness to submit to God. It is hatred of his law, hatred of his government, hatred of his plans, and hatred of his character. See (Romans 1:30; John 7:7; John 15:18; John 15:23–25). .

Should have submitted themselves unto him – Margin: "yielded feigned obedience." Hebrew: "lied." See the phrase explained in the notes at (Psalms 18:44). The meaning is that they would have been so subdued as to acknowledge his authority or supremacy, while it is, at the same time, implied that this submission would have been forced and not cordial. No external power, though it may conquer people enough to make them outwardly obedient, can affect or subdue the will. The grace of God alone can do that, and it is the special triumph of grace that it can accomplish this.

But their time – This refers to the time of his people. They would have continued to be a happy and flourishing nation.

Should have endured for ever – Meaning, perpetually, as long as they continued to be obedient. If a nation were obedient to the will of God, if it wholly obeyed his laws, if it countenanced by statute no form of sin, if it protected no iniquity, and if it were temperate, just, virtuous, and honest, there is no reason why its institutions should not be perpetual or why it should ever be overthrown. Sin is, in all cases, the cause of the ruin of nations, as it is of individuals.