Numbers 7:9
Ver. 9. But unto the sons of Kohath he gave none,.... Being all disposed of to the sons of Gershon and Merari: the reason of which follows,
because the service of the sanctuary belonging unto them [was that] they should bear upon their shoulders; as the ark with the mercy seat, and cherubim, the shewbread table, the candlestick, and the two altars; though in later times we find the ark was sometimes not only carried by the priests, but upon a cart, Jos 3:17.