Isaiah 22:
21] And I will clothe him with thy robe, and strengthen him with thy girdle, and I will commit thy government into his hand: and he shall be a father to the inhabitants of Jerusalem, and to the house of Judah.
[22] And the key of the house of David will I lay upon his shoulder; so he shall open, and none shall shut; and he shall shut, and none shall open.
[23] And I will fasten him as a nail in a sure place; and he shall be for a glorious throne to his father's house.
Revelation 3:8
behold, I have set before thee an open door, and no man can shut it: for thou hast a little strength, and hast kept my word, and hast not denied my name.
Rev 3:7 seems more clear. Sure, I don’t have a problem with Isa 22 being a prophecy for the coming Messiah; after all, Jesus gave the keys to St. Peter in Matt 16:19, He obviously therefore HAD them to give! And He will have them during the events described in Rev 3:7-8.
I don’t see how this abrogates or negates the parallel as far as St. Peter would have seen it though. He (St. Peter) would have understood Jesus to be giving him (St. Peter) the same kind of “key” (or keys) mentioned in Isa 22, that is, authority to rule over His Kingdom on Earth.
Now, did he (St. Peter) understand it THEN at that moment? I’m not saying that, so let me be clear there. But looking back at that moment, given his knowledge (he must have had this knowledge) of Isa 22, and after His Resurrection and Ascension, he (St. Peter) would have realized the significance.
Again, the parallel is inescapable, and there’s no way St. Peter didn’t see it either then or more likely after His Ascension.