Charles Ellicott Commentary Ezra 8:20

"and of the Nethinim, whom David and the princes had given for the service of the Levites, two hundred and twenty Nethinim: all of them were mentioned by name." — Ezra 8:20 (ASV)

The Nethinims —It is here alone recorded that David appointed these to aid the Levites.

All of them were expressed by name. —Not, as some think, that they were all famous, but that Iddo sent their names in a list not given. The relief of their coming is gratefully ascribed to the good hand of our God upon us.