In the passage from Revelation, we see Jesus describing Himself. This letting us know something about himself is a major feature of the book aptly named The Revelation of Jesus Christ.
But the mention in Isaiah doesn't seem to have anything to do with Jesus. Here is the text from Isaiah.
15 Thus saith the Lord GOD of hosts, Go, get thee unto this treasurer, even unto Shebna, which is over the house, and say,
16 What hast thou here? and whom hast thou here, that thou hast hewed thee out a sepulchre here, as he that heweth him out a sepulchre on high, and that graveth an habitation for himself in a rock?
17 Behold, the LORD will carry thee away with a mighty captivity, and will surely cover thee.
18 He will surely violently turn and toss thee like a ball into a large country: there shalt thou die, and there the chariots of thy glory shall be the shame of thy lord's house.
19 And I will drive thee from thy station, and from thy state shall he pull thee down.
20 And it shall come to pass in that day, that I will call my servant Eliakim the son of Hilkiah:
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.
We also find Shebna and Hilkiah mentioned in 2 Kings and in Isaiah 37.
And he sent Eliakim, who was over the household, and Shebna the scribe, and the elders of the priests covered with sackcloth, unto Isaiah the prophet the son of Amoz. Isaiah 37:2
Let's look at some other factors. Hilkiah means portion of Jehovah or my portion is Jehovah. Eliakim means whom God establishes or Whom God will raise up or set up.. Shebna means youth or vigour. There are other clues to be found in careful reading of the text. Notice that in Isaiah 22 Shebna is mentioned as being over the house, but in Isaiah 37 and 2 Kings 18 it clearly states that Eliakim was over the household. In Isaiah 22:20 he uses the phrase "And it shall come to pass in that day". This indicates that the passage is prophetic and points to a future time. Also in the same verse he calls Eliakim 'my servant', a phrase associated with Messiah as mentioned in Isaiah 53 and other places. Next consider that Eliakim is always described as the son of Hilkiah while no genealogy is ever given for Shebna. He is always called Shebna, the Scribe. This whole passage about Shebna and Eliakim is only about them on the surface. This is figurative speech contrasting Jesus the Son of God with Satan the legalist. And the passage is really or prophetically speaking of Messiah being established in the place of Satan. Jesus is being set up by the Father, over the household of God where before it had been under the domain or influence of Satan, who is about to be overthrown with great judgments.
Notice that God says He will lay the key of David on his shoulder. There is another passage in Isaiah where we read about the government on his shoulder
Of the increase of his government and peace there shall be no end, upon the throne of David, and upon his kingdom, to order it, and to establish it with judgment and with justice from henceforth even for ever. The zeal of the LORD of hosts will perform this. Isaiah 9:6-7
The Key of David sets him over the house of David. Or to use the language of Isaiah 9, it gives him the government of the house of David. As we read in Isaiah 22:21b: "and I will commit thy government into his hand, …."
We said before the key speaks of power and authority. Some commentators say that this is a mantle of authority, and thus we can speak of it being set upon someone's shoulders. So in this view, Isaiah 22 says that, God is saying He will give Jesus the government once held by Satan and give him all power and authority.
But if verse 21a it says " And I will clothe him with thy robe …. So the key may not be an article of clothing. Besides, if it referred to a mantle, like the mantle of Samuel, or of Elijah, then it would rest on both shoulders!
In this case the key is speaking of something required to exercise power and authority. It is not the power and authority itself. Just as a key is required to open or shut a door, the Key of David is required to exercise power and authority. And the clue here is the shoulder. And the key is the Cross which he bore on his shoulder. For it was not till after He went to the cross and rose again that he came and told his followers :"… All power is given unto me in heaven and in earth.
Wherefore God also hath highly exalted him, and given him a name which is above every name:
That at the name of Jesus every knee should bow, of things in heaven, and things in earth, and things under the earth;
And that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father. Philippians 2:8-11
Yet it pleased the LORD to bruise him; he hath
put him to grief: when thou shalt make his soul an offering for sin, he
shall see his seed, he shall prolong his days, and the pleasure of the
LORD shall prosper in his hand.
He shall see of the travail of his soul, and
shall be satisfied: by his knowledge shall my righteous servant justify
many; for he shall bear their iniquities.
Therefore will I divide him a portion with the
great, and he shall divide the spoil with the strong; because he hath poured
out his soul unto death: and he was numbered with the transgressors; and
he bare the sin of many, and made intercession for the transgressors. Isaiah
53:10 12
The cross was the wooden altar that the perfect sacrifice was offered upon.
As his feet were nailed to the cross, you could say that the cross is his footstool and also his throne, for because of the Cross, he reigns.
And because he reigns he can extend to the church a promise to rule and reign with him.
Yea, and all that will live godly in Christ Jesus shall suffer persecution. 2 Tim 3:12
Walk about Zion, and go round about her: tell the towers thereof.
Mark ye well her bulwarks, consider her palaces; that ye may tell it to the generation following.
For this God is our God for ever and ever: he will be our guide even unto death. Psalm 48:11-14
Fear none of those things which thou shalt suffer: behold, the devil shall cast some of you into prison, that ye may be tried; and ye shall have tribulation ten days: be thou faithful unto death, and I will give thee a crown of life. Revelation 2:10
And they overcame him by the blood of the Lamb, and by the word of their testimony; and they loved not their lives unto the death. Revelation 12:11
And I saw thrones, and they sat upon them, and judgment was given unto them: and I saw the souls of them that were beheaded for the witness of Jesus, and for the word of God, and which had not worshipped the beast, neither his image, neither had received his mark upon their foreheads, or in their hands; and they lived and reigned with Christ a thousand years. Rev 20:4