Numbers 7:9

But to the sons of Kohath he gave none, because the service of the sanctuary belonged to them; they carried it on their shoulders.

Numbers 3:31

Their duty shall be the ark, the table, the lamp stand, the altars, the vessels of the sanctuary with which they minister, and the screen, and all its service.

2 Samuel 6:13

It was so, that, when those who bore the ark of Yahweh had gone six paces, he sacrificed an ox and a fattened calf.

Numbers 4:4-16

"This is the service of the sons of Kohath in the Tent of Meeting, the most holy things.

2 Samuel 6:6

When they came to the threshing floor of Nacon, Uzzah put forth [his hand] to the ark of God, and took hold of it; for the cattle stumbled.

1 Chronicles 15:3

David assembled all Israel at Jerusalem, to bring up the ark of Yahweh to its place, which he had prepared for it.

1 Chronicles 15:13

For because you didn't carry it at first, Yahweh our God made broke out against us, because we didn't seek him according to the ordinance."

1 Chronicles 23:26

Also the Levites will no longer need to carry the tabernacle and all its vessels for its service."

Treasury of Scripture Knowledge

Summary

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.

Bible References

Because

Numbers 3:31
Their duty shall be the ark, the table, the lamp stand, the altars, the vessels of the sanctuary with which they minister, and the screen, and all its service.
Numbers 4:4
"This is the service of the sons of Kohath in the Tent of Meeting, the most holy things.
2 Samuel 6:6
When they came to the threshing floor of Nacon, Uzzah put forth [his hand] to the ark of God, and took hold of it; for the cattle stumbled.
1 Chronicles 15:3
David assembled all Israel at Jerusalem, to bring up the ark of Yahweh to its place, which he had prepared for it.
1 Chronicles 23:26
Also the Levites will no longer need to carry the tabernacle and all its vessels for its service."