Albert Barnes Commentary Psalms 66:3

"Say unto God, How terrible are thy works! Through the greatness of thy power shall thine enemies submit themselves unto thee." — Psalms 66:3 (ASV)

Say to God – In your songs of praise. Let your songs be directly addressed to Him, setting forth the grounds of that praise, or the reasons why it is due to Him.

How terrible are You in Your works! – How fearful! How much to be reverenced! The meaning is that the manifestations of His power and greatness, in the events which occur under His government, are suited to impress the mind with awe and reverence.

Through the greatness of Your power – By the putting forth of Your power. Or, You have such power over Your enemies as to be able to compel them to submit to You.

Shall Your enemies submit to You – Margin: Lie, or yield feigned obedience. The Hebrew word means to lie, to speak lies; then, to feign, to flatter, to play the hypocrite. It is thus applied to the vanquished, who make a hollow profession of submission and love to their victors. See the word explained in the notes at Psalm 18:44; compare Psalm 81:15, Deuteronomy 33:29, and Job 31:28.

The meaning here is that He had power to subdue them and to compel them to acknowledge His right to reign. It is the putting forth of mere power which is referred to here, and all that such power can do is to secure outward and feigned submission. It cannot of itself secure the submission of the heart, the will, and the affections.

That is to be secured by love, not by power. The difference between the submission of the true people of God and that of all others is that the former are subdued by love, the latter by power; the submission of the former is genuine, while that of the latter is forced.

The inhabitants of heaven will be submissive to God because they love Him; the dwellers in hell will be restrained by power because they cannot deliver themselves. So now, the submission of a true child of God is that of love, or is a willing submission; the submission of a hypocrite is that of fear, when he feigns obedience because he cannot help it, or because he simply dreads the wrath of God.

The object here is to celebrate the power of God, and it was sufficient, in order to set that forth, to say that it awed and outwardly subdued the enemies of God.