Just so everyone is aware of the relevant Scripture Jesus was fulfilling…
15Thus says the LordGodof hosts, “Come, go to this steward, to Shebna, who is over the household, and say to him:16What have you to do here and whom have you here, that you have hewn here a tomb for yourself, you who hew a tomb on the height, and carve a habitation for yourself in the rock?17Behold, theLordwill hurl you away violently, O you strong man. He will seize firm hold on you,18and whirl you round and round, and throw you like a ball into a wide land; there you shall die, and there shall be your splendid chariots, you shame of your master’s house.19I will thrust you from your office, and you will be cast down from your station.20In that day I will call my servant Eli′akim the son of Hilki′ah,21and I will clothe him with your robe, and will bind your girdle on him, and will commit your authority to his hand; and he shall be a father to the inhabitants of Jerusalem and to the house of Judah.22And I will place on his shoulder the key of the house of David; he shall open, and none shall shut; and he shall shut, and none shall open.23And I will fasten him like a peg in a sure place, and he will become a throne of honor to his father’s house.24And they will hang on him the whole weight of his father’s house, the offspring and issue, every small vessel, from the cups to all the flagons.25In that day, says theLordof hosts, the peg that was fastened in a sure place will give way; and it will be cut down and fall, and the burden that was upon it will be cut off, for theLordhas spoken.”
In this passage, we see what Jesus was doing with His words. He was founding an office, and the holder is regarded as “a” father to the whole house of Judah. This office is called “steward”
It makes sense that Jesus acknowledges His Father as revealing to Peter in order for Christ to establish him as the founding holder of this office.
All the terminology is there,… rock, keys, open/shut, office, etc