Ambrose of Milan : Moses himself says in his song, "You sent your Spirit, and the sea covered them." You observe that even then holy baptism was prefigured in that passage of the Hebrews, wherein the Egyptian perished, the Hebrew escaped. For what else are we daily taught in this sacrament but that guilt is swallowed up and error done away, but that virtue and innocence remain unharmed? — On the Mysteries 3.12