How terrible art thou - Consider the plagues with which he afflicted Egypt before he brought your fathers from their captivity, which obliged all his enemies to submit.
Thine enemies submit themselves - Literally, lie unto thee. This was remarkably the case with Pharaoh and the Egyptians. They promised again and again to let the people go, when the hand of the Lord was upon them: and they as frequently falsified their word.
Say unto 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 art thou in thy 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 thy power - By the putting forth of thy power. Or, Thou hast such power over thine enemies as to be able to compel them to submit to thee.
Shall thine enemies submit themselves unto thee - Margin, Lie, or yield reigned 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; 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 here referred to; and all that such power can do, is to secure outward and reigned 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; and 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, 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.