Ezra 2:55

(55) The children of Solomon’s servants.—These are mentioned in 1 Kings 9:0 as a servile class, formed of the residue of the Canaanites. They were probably inferior to the Nethinims, but are generally classed with them, as in the general enumeration here. Both these classes retained during their captivity their attachment to the service into which they had been received; and, the Levites being so few, their value in the reconstitution of the Temple gave them the special importance they assume in these books.