John Gill Commentary Nehemiah 11:21

"But the Nethinim dwelt in Ophel: and Ziha and Gishpa were over the Nethinim." — Nehemiah 11:21 (ASV)

But the Nethinims dwelt in Ophel
An high place or tower on the wall of Jerusalem, see (2 Chronicles 27:3) ,

and Ziha, and Gispa, were over the Nethinims ;
had the oversight of them, and took care that they did their work; they were such themselves, but the principal of them, see (Ezra 2:43) .