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 9:19

9:19 For when Moses had spoken every command to all the people according to the law, he took the blood of calves and goats with water and scarlet wool and hyssop and sprinkled both the book itself and all the people,

Hebrews 10:1

Concluding Exposition: Old and New Sacrifices Contrasted

10:1 For the law possesses a shadow of the good things to come but not the reality itself, and is therefore completely unable, by the same sacrifices offered continually, year after year, to perfect those who come to worship.

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),