There is a difference here from what has been said before: ‘For all the land which thou seest, to thee will I give it.’ Previously, Abram has only been told that it would be given to his seed, but now he is told it will also be given to him.
Abraham symbolizes our pilgrimage here in this world. The believer will not make roots in this world. Abraham stayed in tents lifelong and was a traveller, possessing the land as one who journeyed in it and travelled it and explored it, but he didn't look to the land as if he could establish long-term security for himself there. That was why Nimrod had built Babel. He wanted it for security, to put everybody together, to be strong and then to build his tower. Abraham was content to be obedient, to obey God and be available to him and in service to him, and we must follow in his footsteps. Earth is not our home; we ‘set your affection on things above, not on things on the earth’ (Colossians 3:2).