28. their charge shall be under the hand of Ithamar the son of Aaron, &c.—The Levites were generally subject to the official command of the priests in doing the ordinary work of the tabernacle. But during the journeyings Eleazar, who was next in succession to his father, took the special charge of the Kohathites [Nu 4:16], while his brother Ithamar had the superintendence of the Gershonites and Merarites [Nu 4:33].