Ecclesiastes 1:4

"A generation goes and. generation comes, but the earth remains forever.""One generation enters as another exits, the tragedy manifests itself when men, the highest of God's creation and made from the earth, continually pass away as the earth remains" (Kidwell p. 20).

"remains forever" -which doesn't imply an eternal existence for the planet, for the Hebrew word here rendered "forever" simply means. long age or period. The same word is used in reference to other things which are not eternal in duration, the land promise (Genesis 17:8), circumcision (Ecclesiastes 17:13), the Passover feast (Ex. Ecclesiastes 12:14), the priesthood of Aaron (Ex. Ecclesiastes 29:9), the Sabbath Day (Ex. Ecclesiastes 31:16-17). The word "forever" was rightly used of such things, because all these things lasted during the entire age for which they were designed. The earth is the permanent ground or scene on which all generations will come and go. This is the permanent stage for man's physical history. But one day that stage will be removed (2 Peter 3:10; Revelation 20:11; Ecclesiastes 21:1). What this tells us is that the earth will last as long as God needs it to last. Another planet won't be needed for our habitation-prior to the Second Coming. And, man won't destroy himself or the earth (Genesis 8:22).