John Gill Commentary Genesis 35:12

"and the land which I gave unto Abraham and Isaac, to thee I will give it, and to thy seed after thee will I give the land." — Genesis 35:12 (ASV)

And the land which I gave Abraham and Isaac, to you will I
give it
Meaning the land of Canaan, which, as he had by promise given it to his grandfather, and father, so he would give it to him; thus renewing the grant of it for his comfort, and the encouragement of his faith, when he had been in danger of being destroyed by the inhabitants of it, and was obliged to remove from one part of it to another: and to your seed after you will I give the land ;
and not only make a grant of it to them, but put them into the possession of it, as in process of time he did.