Exodus 29:2

29:2 and bread made without yeast, and perforated cakes without yeast mixed with oil, and wafers without yeast spread with oil – you are to make them using fine wheat flour.

Numbers 18:26-32

18:26 “You are to speak to the Levites, and you must tell them, ‘When you receive from the Israelites the tithe that I have given you from them as your inheritance, then you are to offer up from it as a raised offering to the Lord a tenth of the tithe. 18:27 And your raised offering will be credited to you as though it were grain from the threshing floor or as new wine from the winepress. 18:28 Thus you are to offer up a raised offering to the Lord of all your tithes which you receive from the Israelites; and you must give the Lord’s raised offering from it to Aaron the priest. 18:29 From all your gifts you must offer up every raised offering due the Lord, from all the best of it, and the holiest part of it.’

18:30 “Therefore you will say to them, ‘When you offer up the best of it, then it will be credited to the Levites as the product of the threshing floor and as the product of the winepress. 18:31 And you may eat it in any place, you and your household, because it is your wages for your service in the tent of meeting. 18:32 And you will bear no sin concerning it when you offer up the best of it. And you must not profane the holy things of the Israelites, or else you will die.’”

Hebrews 5:1

5:1 For every high priest is taken from among the people and appointed to represent them before God, to offer both gifts and sacrifices for sins.

Hebrews 7:27

7:27 He has no need to do every day what those priests do, to offer sacrifices first for their own sins and then for the sins of the people, since he did this in offering himself once for all.

Hebrews 8:3-4

8:3 For every high priest is appointed to offer both gifts and sacrifices. So this one too had to have something to offer. 8:4 Now if he were on earth, he would not be a priest, since there are already priests who offer the gifts prescribed by the law.