Caleb was not a native Israelite; he was from Midian to the far south. At Mount Sinai, Moses met up with his father-in-law, Jethro the Kenite (Judges 1:16), priest of Midian. He invited Jobab, Jethro’s son, and his family to come along with Israel to Canaan, but Hobab declined (Numbers 10:29–32). Even so, some Midianites did go along with Israel, among which was Caleb. Caleb gets identified with the tribe of Judah (Numbers 34:19), but he is a Kenite (or Kenizzite; Numbers 32:12). Kenites joined with Israel in the conquest and settled the land with Israel.
1
Of the twelve spies of Numbers 13:1–33, Caleb and Joshua were the two faithful ones. These two had silenced the naysaying spies, with a minority report. They had confidence in the Lord’s power to deliver the Canaanites into their hand (Numbers 13:30; Numbers 14:5–10). Since Caleb trusted the Lord, the Lord rewarded him (through Moses and Joshua) by promising him the major allotment of Hebron within Judah (Joshua 15:13). Caleb resurfaces here, as an old man. When all of his unfaithful generation died, he remained strong in faith. That faith continued in Judges.
2 His challenge to anyone to capture nearby Debir (presumably within his own allotment) reflects his eagerness to see the conquest move forward. By offering his daughter as a reward, he not only expresses his commitment to the agenda but also ensures a noble husband for her.
3
12 And Caleb said, “He who attacks Kiriath-sepher and captures it, I will give him Achsah my daughter for a wife.”