2 Samuel 5:7-9

But David did take the city of Jerusalem with its strong walls, and it became the City of David. That day David said to his men, “To defeat the Jebusites you must go through the water tunnel. Then you can reach those ‘crippled’ and ‘blind’ enemies. This is why people say, ‘The blind and the crippled may not enter the palace.’ ” So David lived in the strong, walled city and called it the City of David. David built more buildings around it, beginning where the land was filled in. He also built more buildings inside the city.