O give thanks unto the God of gods - See Deuteronomy 10:17. The supreme God; the God superior to all that is called God, or that is adored by the nations of the earth; above all to whom the name God is ever applied.
For his mercy... - The ground of praise here is, that it is a characteristic of the supreme God that he is a merciful Being; that there is blended in his character eternal mercy with infinite power. Mere power might fill us with dread; power mingled with mercy, and able to carry out the purposes of mercy, must lay the foundation for praise.

The God of gods - לאדני האדנים ladonai haadonim. As adonai signifies director, etc., it may apply here, not to idols, for God is not their god; but to the priests and spiritual rulers; as Lord of lords may apply to kings and magistrates, etc. He is God and ruler over all the rulers of the earth, whether in things sacred or civil.

O give thanks unto the God of gods,.... Not only of the gods of the Gentiles, who are by name and not by nature gods; or of civil magistrates, who are so called, and seem to be designed in the next verse; but the angels, as Aben Ezra and Kimchi. Christ, our Immanuel, is the God of them, the object of their worship and adoration, being their Creator and Preserver, Psalm 97:7. So the Heathens say (r) of the Maker of all things, him you may properly call the God of gods, the Supreme and Best; this title Janus has with them (s);
for his mercy endureth for ever; in the preservation of those excellent creatures from apostasy, when many of their species fell; and in the continuance and confirmation of them in the state in which they were created; and in making use of them as ministering spirits to the heirs of salvation; and as a guard about them while they live, and at death to convey their souls to heaven.
(r) Hierocles in Carm. Pythagor. p. 10. (s) Macrob. Saturnal. l. 1. c. 9.

The God of gods - Who is infinitely superior to all that are called gods, whether angels, or princes, or idols.