John Calvin Commentary Psalms 105:27

"They set among them his signs, And wonders in the land of Ham." — Psalms 105:27 (ASV)

They set among them the words of his signs. The prophet, in the first place, briefly glances at those things that Moses has detailed at greater length. Nor does he follow the order of the events observed in the history, for he contents himself with showing that the deliverance of the chosen people was the work of God. He again distinguishes between the power of God and the ministry of Moses and Aaron. He indeed asserts that these men performed miracles, but these miracles proceeded from God, so that celestial power was not obscurely displayed by their instrumentality.

In the 28th verse, he specifies one of these miracles, which, however, was not the first in order, but from which it is easy to gather that God was the author of the deliverance of Israel, and in which the course of nature was entirely changed; for nothing is more astonishing than to see light turned into darkness. In the second clause, he commends the faithfulness of Moses and Aaron in courageously executing whatever God had commanded them: And they were not rebellious against his words. There was, as it were, the most perfect harmony between the command of God and the obedience of both his servants.