Halakhah sa Mga Bilang 7:9: Mishneh Torah, Sabbath, Mishneh Torah, Positive Mitzvot & Sefer HaChinukh

One who carries [an object] is liable – whether with his right [hand], with his left, in his lap, or [whether] he left with money tied in his sheet – since he carried [an object] in the way of those that carry. Likewise, one who carries [it] on his shoulder is liable – even though the load is above ten handbreadths in the public domain. As the load of the Sons of Kehat was likewise above ten in the Tabernacle, as it is stated (Num. 7:9), “they carried on the shoulder.” And we learn all of the forbidden types of work from the Tabernacle.

That, when the Ark is carried, it should be carried on the shoulder, as it is said, “They shall bear it upon their shoulder” (Num. 7:9).

The commandment of carrying the Ark on the shoulder: That the priests (Kohanim) are commanded to carry the Ark on their shoulders when the People of Israel move it from one place to another, as it is stated (Numbers 7:9), “for the holy service is upon them, they shall carry on their shoulders.” Rabbi Moshe ben Maimon (Maimonides), may his memory be blessed, wrote (Sefer HaMitzvot, Positive Commandments 34) [that] even though this commandment came to the Levites, that was [only] at that time — meaning to say in the wilderness, due to the small number of Kohanim at that time. In [future] generations, however, the Kohanim were obligated in this commandment — and they shall carry it — as is elucidated from the Book of Joshua and the Book of Samuel.