A.T. Robertson Commentary Acts 7:5

"and he gave him none inheritance in it, no, not so much as to set his foot on: and he promised that he would give it to him in possession, and to his seed after him, when [as yet] he had no child." — Acts 7:5 (ASV)

Not so much as to set his foot on (ουδε βημα ποδος). From De 2:5. Old word from βαινω, 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 (Matthew 27:19). The field purchased by Abraham (Genesis 23:9–17) was not a gift from God.

Promised (επηγγειλατο). First aorist middle indicative of επαγγελλω, common verb. See Ge 12:7; 17:8; 48:4 for this promise. So God appeared again to Abraham in a strange land.

In possession (εις κατασχεσιν). Late word, in LXX, and in N.T. only here and verse 45. From κατεχω, 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 (ουκ οντος αυτω τεκνου). Genitive absolute with negative ουκ rather than μη to emphasize actual absence of a child. He had only the promise of God about the land and the child.