John Calvin Commentary Isaiah 51:10

"Is it not thou that driedst up the sea, the waters of the great deep; that madest the depths of the sea a way for the redeemed to pass over?" — Isaiah 51:10 (ASV)

Which dried up the sea. Though Isaiah does not relate all the miracles which God performed when he brought out his people from the bondage of Egypt, yet he intended to include in a few words all that are related by Moses, so that the Jews, having been briefly addressed, might consider the various ways in which the Lord had demonstrated his power.

The drying up of the Red Sea is mentioned, not only because of the extraordinary excellence of the miracle, but also because the numerous miracles which preceded it were directed to this end: that the people, rescued from unjust violence and tyranny, might pass into the promised land. Accordingly, the Prophet expressly mentions that a way was opened up for the redeemed.

From this example we ought to consider what God will be to us, so that we draw this conclusion: that in the future God will always be like himself, as is evident from the context.