Hebrews 7:5

7:5 And those of the sons of Levi who receive the priestly office have authorization according to the law to collect a tithe from the people, that is, from their fellow countrymen, although they too are descendants of Abraham.

Hebrews 10:8

10:8 When he says above, “Sacrifices and offerings and whole burnt offerings and sin-offerings you did not desire nor did you take delight in them” (which are offered according to the law),