The word for “forever” is OLAM. “olam: long duration, antiquity, futurity”: biblehub.com/hebrew/5769.htm
Heaven and earth will pass away, but My words will never pass away. (Mt.24:35)
But the day of the Lord will come as a thief in the night; in the which the heavens shall pass away with a great noise, and the elements shall melt with fervent heat, the earth also and the works that are therein shall be burned up. (2 Pet.3:10)
Then I saw a great white throne and the One who sat on it. The earth and the heavens fled from His presence, and no place was found for them. (Rev.20:11)
25"Of old You founded the earth, And the heavens are the work of Your hands. 26"Even they will perish, but You endure; And all of them will wear out like a garment; Like clothing You will change them and they will be changed.27"But You are the same, And Your years will not come to an end. (Psa.102)
"See, I will create new heavens and a new earth. The former things will not be remembered, nor will they come to mind. (Isa.65:17)
2 Peter 3:13
But in keeping with God’s promise, we are looking forward to a new heaven and a new earth, where righteousness dwells.
Revelation 21:1
Then I saw a new heaven and a new earth, for the first heaven and earth had passed away, and the sea was no more.
Matthew 5:18
For I tell you truly, until heaven and earth pass away, not a single jot, not a stroke of a pen, will disappear from the Law until everything is accomplished.
Mark 13:31
Heaven and earth will pass away, but My words will never pass away.
Luke 21:33
Heaven and earth will pass away, but My words will never pass away.