2 Chronicles 33:13-14

13When he prayed to the Lord, the Lord responded to him and answered favorably his cry for mercy. The Lord brought him back to Jerusalem to his kingdom. Then Manasseh realized that the Lord is the true God.

14After this Manasseh built up the outer wall of the City of David on the west side of the Gihon in the valley to the entrance of the Fish Gate and all around the terrace; he made it much higher. He placed army officers in all the fortified cities in Judah.