Psalms 106:21

They forgat God their Saviour ,.... Not only forgat the works of God, Psalm 106:13 , but forgat God that did those mighty works; forgat that there was a God; or however forgat him that is the only true and living God, when they said of the molten image, "these are thy gods, O Israel"; and what aggravated their crime was, they forgot that God that had saved them in so wonderful a manner out of the hand of their enemies, for his own name's sake; and had led them safely through the Red sea as on dry land, and destroyed those that hated them.

Which had done great things in Egypt : meaning the ten plagues on the Egyptians, and the deliverance of the Israelites from them.