Not so much as to set his foot on (oude bēma podos). From Deu 2:5. Old word from bainō, to go, to step. “Stepping of a foot,” only instance of this original meaning in the N.T. From this it comes to mean a platform reached by steps, official seat of a judge (Mat 27:19). The field purchased by Abraham (Gen 23:9-17) was not a gift from God.
Promised (epēggeilato). First aorist middle indicative of epaggellō, common verb. See Gen 12:7; Gen 17:8; Gen 48:4 for this promise. So God appeared again to Abraham in a strange land.
In possession (eis kataschesin). Late word, in lxx, and in N.T. only here and Act 7:45. From katechō, to hold back, then to hold fast (or down), to possess. It was fulfilled in the descendants of Abraham.
When as yet he had no child (ouk ontos autōi teknou). Genitive absolute with negative ouk rather than mē to emphasize actual absence of a child. He had only the promise of God about the land and the child.