Whether Caleb was getting old and unable to fight when he made the following offer, I do not know, but it certainly motivated someone,

Then Caleb said,

“Whoever attacks Kirjath Sepher and takes it, to him I will give my daughter Achsah as wife.” And Othniel the son of Kenaz, Caleb’s younger brother, took it; so he gave him his daughter Achsah as wife (Judges 1:12–13).

Either Achsah was very good looking, or she was a wonderful spiritual woman, or she was simply Caleb’s daughter, or all three, or something else, anyway, whatever it was, it motivated Caleb’s nephew and he attacked and took the city.

Caleb kept his word, and we hope that Othniel and Achsah had a wonderful life in the promises of God together.