Psalms 135:8

Who smote the firstborn of Egypt, both of man and beast. Which was the last of the plagues inflicted on the Egyptians; and is particularly mentioned, because, by means of it, they were made willing to let the children of Israel go out of their land: and so this includes the deliverance of the Israelites, God's firstborn, when he slew the firstborn of Egypt; and who were typical of the firstborn, whose names are written in heaven; and the deliverance of them, through the blood of the passover, was an emblem of the deliverance of those by the blood of Christ; see Exodus 12:22.