The Nethinims dwelt in Ophel Which was upon the wall of Jerusalem, because they were to do the servile work of the temple; therefore they were to be posted near it, that they might be ready to attend.
Related Commentaries of Nehemiah 11:21
Nehemiah 11:21
21 But the Nethinims dwelt in Ophel:d and Ziha and Gispa were over the Nethinims.