If Jesus told Peter that he is going to do something that means that He has already foreseen the outcome and that even His telling Peter what he was going to do wasn’t going to change that outcome. I’m not saying that Peter didn’t have a choice, I’m saying that Jesus knew what his choice would be.
So, when Isaiah told Hezekiah that God had foreseen that Hezekiah was going to die of his illness, then It didn't do Hezekiah any good and Hezekiah died from that illness, BECAUSE God had already foreseen his early death??
[Isa 38:1 NKJV] In those days Hezekiah was sick and near death. And Isaiah the prophet, the son of Amoz, went to him and said to him, "Thus says the LORD: 'Set your house in order, for you shall die and not live.' "
[Isa 38:2 NKJV] Then Hezekiah turned his face toward the wall, and prayed to the LORD,
[Isa 38:3 NKJV] and said, "Remember now, O LORD, I pray, how I have walked before You in truth and with a loyal heart, and have done [what is] good in Your sight." And Hezekiah wept bitterly.
[Isa 38:4 NKJV] And the word of the LORD came to Isaiah, saying,
[Isa 38:5 NKJV] "Go and tell Hezekiah, 'Thus says the LORD, the God of David your father: "I have heard your prayer, I have seen your tears; surely I will add to your days fifteen years.
What did God foresee? The only outcome, where Hezekiah died early? Or was it NOT the only outcome, meaning that God knew of two possible futures for Hezekiah that were contradictory to each other (i.e., they weren't both actual futures)?
Now, if Hezekiah had two possible futures, why couldn't Peter have had two possible futures? And if either one is possible for Peter when Peter hears the Lord, then God isn't actually seeing the future, but seeing something else, like "possible futures" or, even better, He's seeing what Peter is like and how weak he is in the area that Satan will be tempting him.