It is clear in the text that both pharaoh and God hardened Pharaohs heart. There are many text in the OT that speak of other ways in which God hides Himself from people.
Matthew 13
10Then the disciples came and said to him, “Why do you speak to them in parables?” 11And he answered them, “To you it has been given to know the secrets of the kingdom of heaven, but to them it has not been given. 12For to the one who has, more will be given, and he will have an abundance, but from the one who has not, even what he has will be taken away. 13This is why I speak to them in parables, because seeing they do not see, and hearing they do not hear, nor do they understand. 14Indeed, in their case the prophecy of Isaiah is fulfilled that says:
“‘“You will indeed hear but never understand, and you will indeed see but never perceive.” 15For this people’s heart has grown dull, and with their ears they can barely hear, and their eyes they have closed, lest they should see with their eyes and hear with their ears and understand with their heart and turn, and I would heal them.’
