Now the promise to Abraham as it regarded his physical seed national Israel entering into the land of promise , God hath fulfilled as per Josh 21:43 points out. Abraham was not personally promised this land.
But, the Land promise that Abraham was personally promised to receive along with His Spiritual seed, this land promise would not be fulfilled for Abraham and His seed until the resurrection morning. In this promise all the Patriarchs died in Faith not receiving the promise Heb 11:13
These all died in faith, not having received the promises, but having seen them afar off, and were persuaded of them, and embraced them, and confessed that they were strangers and pilgrims on the earth.
We know that they perceived these promises of Land to be spiritual and heavenly because they seen them by Faith, not the Faith of the natural man, but of the Spiritual kind. This faith caused them to confess that they were pilgrims and strangers on the earth, so the land obviously was not of this earth they sought after and desired as a result of the promise.
Now here are some Facts about the two covenant promises to keep in mind !
To Abrahams Physical seed the land promise was fulfilled, to Abraham personally and His spiritual seed, it will be fulfilled .
To Abraham's physical seed, there was no guarantee of continuity, but to Abraham and His Spiritual seed, it will be a eternal possession !
To Abraham' physical seed, their possession of the Land was conditioned by continued obedience to the national covenant or they would lose their inheritance as per Deut 8:18-20
18 But thou shalt remember the LORD thy God: for it is he that giveth thee power to get wealth, that he may establish his covenant which he sware unto thy fathers, as it is this day.
19 And it shall be, if thou do at all forget the LORD thy God, and walk after other gods, and serve them, and worship them, I testify against you this day that ye shall surely perish.
20 As the nations which the LORD destroyeth before your face, so shall ye perish; because ye would not be obedient unto the voice of the LORD your God.
But to Abraham and His Spiritual seed the land promise is unconditional and eternal..
The one promise was for national Israel, Abraham's Physical natural seed, but the other promise included Abraham and all who believed on Christ Gal 3:7,29
7 Know ye therefore that they which are of faith, the same are the children of Abraham.
29 And if ye be Christ's, then are ye Abraham's seed, and heirs according to the promise.
The promises that God made to Abraham concerning national Israel, have been completely fulfilled as per Joshua 21:41-45; Neh 9:7-8, so God owes them no more from any promise that He gave to Abraham.
The promises that God gave to Abraham regarding both He and His seed, which includes all who believe in Christ per Gal 3:7, 29 have not yet been fulfilled, but will be fulfilled in the New Earth. The city the patriarchs were looking for was one whose builder and maker is God as per Heb 11:10
10 For he looked for a city which hath foundations, whose builder and maker is God.
That means He look for an inheritance in the New Jerusalem, not a earthly Jerusalem, which was made by men. 4