Upvote:2
'I will harden' indicates that God's presence (the very presence of he who is I AM) causes a hardening of the wicked heart.
'I (being present) will (cause to) harden the heart of Pharoah.'
That the heart of the wicked hardens in the presence of I AM ( that is to say when Moses is present and God is with Moses) is entirely due to them.
It is their own culpability.
I think the burden of 'proof' or the necessity of 'evidence' is upon those who assert that God, who alone is righteous, is 'responsible' for sin.
If this be regarded as a merely philosophical question then it would be off-topic on this site.