John Calvin Commentary Psalms 77:19

"Thy way was in the sea, And thy paths in the great waters, And thy footsteps were not known." — Psalms 77:19 (ASV)

Your ways are in the sea. The miracle performed in drying up the Red Sea is here again described in different wording. What properly refers to the Israelites is applied to God, under whose protection and guidance they passed dry-footed through the middle of the Red Sea.

It is declared that a path was opened for them in a very strange and unusual manner. For the sea was not drained by human skill, nor was the River Jordan turned aside from its ordinary course into a different channel; instead, the people walked through the middle of the waters in which Pharaoh and his whole army were soon after drowned. On this account, it is said that Your footsteps were not known, because no sooner had God made the people pass over than He caused the waters to return to their accustomed course.

The purpose for which this was accomplished is added in the 20th verse (Psalms 77:20)—the deliverance of the Church: You led Your people like a flock. And this deliverance should be regarded by all the godly as giving them the best encouragement to cherish the hope of safety and salvation.

The comparison of the people to sheep quietly implies that they were in themselves entirely lacking wisdom, power, and courage.

It further implies that God, in His great goodness, condescended to perform the office of a shepherd. He led His poor flock—which was lacking everything—through the sea, the wilderness, and all other obstacles, so that He might put them in possession of the promised inheritance.

This statement is confirmed when we are told that Moses and Aaron were the persons employed in leading the people. Their service was undoubtedly illustrious and worthy of being remembered. However, God significantly displayed the greatness of His power by opposing two obscure and despised individuals to the fury and the great and powerful army of one of the proudest kings who ever sat on a throne.

What could the rod of an outlaw and a fugitive, and the voice of a poor slave, have done by themselves against a formidable tyrant and a warlike nation? The power of God, then, was all the more manifest when it worked in such earthen vessels. At the same time, I do not deny that this passage also intends to commend these servants of God, to whom He had committed such an honorable trust.