Anf-01 ix.vi.xxx Pg 8
Ex. iii. 19.
And for the reason that the Lord spake in parables, and brought blindness upon Israel, that seeing they might not see, since He knew the [spirit of] unbelief in them, for the same reason did He harden Pharaoh’s heart; in order that, while seeing that it was the finger of God which led forth the people, he might not believe, but be precipitated into a sea of unbelief, resting in the notion that the exit of these [Israelites] was accomplished by magical power, and that it was not by the operation of God that the Red Sea afforded a passage to the people, but that this occurred by merely natural causes (sed naturaliter sic se habere).