And Caleb said, He that smiteth Kirjathsepher, and taketh it, to him will I give Achsah my daughter to wife.

Wesley's Notes

15:16 To wife - Which is to be understood with some conditions, as, if he were one who could marry her by God's law; and if she were willing; for though parents had a great power over their children, they could not force them to marry any person against their own wills. He might otherwise be an unfit and unworthy person; but this was a divine impulse, that Othniel's valour might be more manifest, and so the way prepared for his future government of the people, Judg 3:9.

Jamieson-Fausset-Brown Bible Commentary

Jos 15:16-20. Othniel, for His Valor, Has Achsah to Wife.

16-20. He that smiteth Kirjath-sepher-This offer was made as an incentive to youthful bravery (see on [196]1Sa 17:25); and the prize was won by Othniel, Caleb's younger brother (Jud 1:13; 3:9). This was the occasion of drawing out the latent energies of him who was destined to be the first judge in Israel.

Matthew Henry's Concise Commentary

15:13-19 Achsah obtained some land by Caleb's free grant. He gave her a south land. Land indeed, but a south land, dry and apt to be parched. She obtained more, on her request, and he gave the upper and the nether springs. Those who understand it but of one field, watered both with the rain of heaven, and the springs that issued out of the earth, countenance the allusion commonly made to this, when we pray for spiritual and heavenly blessings which relate to our souls, as blessings of the upper springs, and those which relate to the body and the life that now is, as blessings of the nether springs. All the blessings, both of the upper and the nether springs, belong to the children of God. As related to Christ, they have them freely given of the Father, for the lot of their inheritance.