You trampled the sea with your horses, the surging of mighty waters.
Some read, “Thou hast trodden thy horses in the sea;” but it is a solecism, that is quite evident. Others, “Thou hast trodden in the sea by thy horses.” But what need is there of seeking such strained explanations, since the verb דרך, darek, means to go or to march?
It has been the usual practice of God's people, when they have been in distress and ready to fall into despair, to help themselves by recollecting their experiences, and reviving them, considering the days of old, and the years of ancient times (Psa 77:5), and pleading with God in prayer, as he is pleased sometimes to plead them with himself. Isa 63:11, Then he remembered the days of old.
Commenting on Habakkuk 3:3-15
Thou didst walk through the sea with thine horses,.... And as thou didst of old, so do again; as Jehovah walked through the Red sea in a pillar of cloud and fire, which were his horses and chariots, and destroyed the Egyptians; so may he walk through another sea by his instruments, and destroy the enemies of his church and people; See Gill on Hab 3:8.