1 Corinthians 9:13-14

Do ye not know, that they who minister in the offerings of the temple live from the temple? that they who serve at the altar share with the altar?

Galatians 6:6

Let him that is taught in the word share with the teacher in all good things.

Hebrews 7:5

And those indeed of the sons of Levi who receive the office of the priesthood have a command to take tithes of the people by the Law, that is, of their brethren, though they have come out of the loins of Abraham;

Treasury of Scripture Knowledge

Summary

And, behold, I have given the children of Levi all the tenth in Israel for an inheritance, for their service which they serve, even the service of the tabernacle of the congregation.

Bible References

Even the service

1 Corinthians 9:13
Do ye not know, that they who minister in the offerings of the temple live from the temple? that they who serve at the altar share with the altar?
Galatians 6:6
Let him that is taught in the word share with the teacher in all good things.