'Unable' in the Bible

"You know that my father David was unable to build a temple to honor the Lord his God, for he was busy fighting battles on all fronts while the Lord subdued his enemies.

Their descendants remained in the land (the Israelites were unable to wipe them out completely). Solomon conscripted them for his work crews, and they continue in that role to this very day.

So he said to the messengers of Ben Hadad, "Say this to my master, the king, 'I will give you everything you demanded at first from your servant, but I am unable to agree to this latest demand.'" So the messengers went back and gave their report.