They were men taken captive during the conquest of the land. Some of these captives were later made available to the Levites to help with the work at the tabernacle. ​ — Ezra 8: 20.
אלה היו גברים שנשבו במהלך כיבוש הארץ, וחלקם ניתנו ללוויים כדי לעזור בעבודות המשכן (‏ עזרא ח ’: 20‏) .‏