The words "Once more" signify the removal of what can be shaken--that is, created things--so that the unshakable may remain.

Isaiah 34:4
All the stars of heaven will be dissolved. The skies will be rolled up like a scroll, and all their stars will fall like withered leaves from the vine, like foliage from the fig tree.

Isaiah 54:10
Though the mountains may be removed and the hills may be shaken, My loving devotion will not depart from you, and My covenant of peace will not be broken," says the LORD, who has compassion on you.

Isaiah 65:17
For behold, I will create new heavens and a new earth. The former things will not be remembered, nor will they come to mind.

Isaiah 66:22
"For just as the new heavens and the new earth, which I will make, will endure before Me," declares the LORD, "so your descendants and your name will endure.

Haggai 2:21
"Tell Zerubbabel governor of Judah that I am about to shake the heavens and the earth:

Romans 8:19
The creation waits in eager expectation for the revelation of the sons of God.

Romans 8:21
that the creation itself will be set free from its bondage to decay and brought into the glorious freedom of the children of God.

1 Corinthians 7:31
and those who use the things of this world, as if not dependent on them. For this world in its present form is passing away.

Hebrews 1:10
And: "In the beginning, O Lord, You laid the foundations of the earth, and the heavens are the work of Your hands.

Hebrews 9:11
But when Christ came as high priest of the good things that have come, He went through the greater and more perfect tabernacle that is not made by hands and is not a part of this creation.

Hebrews 13:14
For here we do not have a permanent city, but we are looking for the city that is to come.

Revelation 21:4
He will wipe away every tear from their eyes,' and there will be no more death or mourning or crying or pain, for the former things have passed away."

Revelation 21:5
And the One seated on the throne said, "Behold, I make all things new." Then He said, "Write this down, for these words are faithful and true."

And this word, Yet once more, signifies the removing of those things that are shaken, as of things that are made, that those things which cannot be shaken may remain.