But unto the sons of Kohath he gave none: because the service of the sanctuary belonging unto them was that they should bear upon their shoulders. Unto the sons of Kohath he gave none - Because they had the charge of the ark, table, candlestick, altars, etc., Numbers 4:5-15, which were to be carried upon their shoulders; for those sacred things must not be drawn by beasts.
Related Commentaries of Numbers 7:9
Numbers 7:9
9 But unto the sons of Kohath he gave none: because the service of the sanctuary belonging unto them was that they should bear upon their shoulders.