“And the LORD spake unto Moses, saying, Speak unto Aaron and to his sons, that they separate themselves from the holy things of the children of Israel, and that they profane not my holy name in those things which they hallow unto me: I am the LORD.” (Leviticus 22:1-2)
Moses was to instruct Aaron and the priests to distinguish between themselves and the holy things to prevent profaning them before the people. They were to keep the things offered to God at arms length to prevent beginning to treat them as their own, or people from feeling like it just belonged to them. If they treated those things as their own, they might use them improperly.
Over the years I have seen a lot of ministries use money that was given for a specific purpose for to buy jet skis, or pay for expensive vacations instead. Donors who had given up their own pleasures and comforts were seriously offended as a result, making it far harder for legitimate ministries to obtain needed help.
“Say unto them, Whosoever he be of all your seed among your generations, that goeth unto the holy things, which the children of Israel hallow unto the LORD, having his uncleanness upon him, that soul shall be cut off from my presence: I am the LORD. What man soever of the seed of Aaron is a leper, or hath a running issue; he shall not eat of the holy things, until he be clean.
And whoso toucheth any thing that is unclean by the dead, or a man whose seed goeth from him; Or whosoever toucheth any creeping thing, whereby he may be made unclean, or a man of whom he may take uncleanness, whatsoever uncleanness he hath; The soul which hath touched any such shall be unclean until even, and shall not eat of the holy things, unless he wash his flesh with water. And when the sun is down, he shall be clean, and shall afterward eat of the holy things; because it is his food.” (Leviticus 22:3-7)
The same health guidelines for uncleanness applied to the priests as well. During the time they were unclean, they were to be isolated from the tabernacle and were not permitted to serve as priests or partake of the offerings until they were again clean to prevent the spread of disease. Once they were clean they could resume their duties.
“That which dieth of itself, or is torn with beasts, he shall not eat to defile himself therewith: I am the LORD. They shall therefore keep mine ordinance, lest they bear sin for it, and die therefore, if they profane it: I the LORD do sanctify them.” (Leviticus 22:8-9)
While ordinary people could eat normally clean animals which had died of natural causes, just taking precautions to protect others, the priest were prohibited from doing so because of their position before God and their constant contact with other people. Failure to do so could result in death of the priest.
“There shall no stranger eat of the holy thing: a sojourner of the priest, or an hired servant, shall not eat of the holy thing. But if the priest buy any soul with his money, he shall eat of it, and he that is born in his house: they shall eat of his meat.” (Leviticus 22:10-11)
The things dedicated to God were to be given to the priests for their personal use and that of their immediate families. They were not to be shared with other people, not even the priest’s visitors or employees, although his own family and slaves could since they were his responsibility.
“If the priest's daughter also be married unto a stranger, she may not eat of an offering of the holy things. But if the priest's daughter be a widow, or divorced, and have no child, and is returned unto her father's house, as in her youth, she shall eat of her father's meat: but there shall no stranger eat thereof.” (Leviticus 22:12-13)
If the priest’s daughter was married to someone who was not a priest, she was not permitted to eat the holy things because her father was no longer responsible to support her. If she was divorced or her husband died, and she was forced to go home as a dependent of her father, she was allowed to partake, but if she had a child she was responsible for she could no longer be fully dependent on her father. She had to take responsibility for her child.
“And if a man eat of the holy thing unwittingly, then he shall put the fifth part thereof unto it, and shall give it unto the priest with the holy thing.” (Leviticus 22:14)
If a person accidentally ate some of the holy things, he was to replace it and add twenty percent of its value to make up for their not having it.
“And they shall not profane the holy things of the children of Israel, which they offer unto the LORD; Or suffer them to bear the iniquity of trespass, when they eat their holy things: for I the LORD do sanctify them.” (Leviticus 22:15-16)
While the holy things were designated to be given to the priests, they were to receive it seriously as belonging to God. They were not to partake, without first taking care of their own sin.
“And the LORD spake unto Moses, saying, Speak unto Aaron, and to his sons, and unto all the children of Israel, and say unto them, Whatsoever he be of the house of Israel, or of the strangers in Israel, that will offer his oblation for all his vows, and for all his freewill offerings, which they will offer unto the LORD for a burnt offering; Ye shall offer at your own will a male without blemish, of the beeves, of the sheep, or of the goats. But whatsoever hath a blemish, that shall ye not offer: for it shall not be acceptable for you.” (Leviticus 22:17-20)
Any offering to God other than the various sin offerings were voluntary gifts. There could be no pressure to give them., but they had to be given with respect to God. Offering him something less than their best was an insult to him.
“And whosoever offereth a sacrifice of peace offerings unto the LORD to accomplish his vow, or a freewill offering in beeves or sheep, it shall be perfect to be accepted; there shall be no blemish therein. Blind, or broken, or maimed, or having a wen, or scurvy, or scabbed, ye shall not offer these unto the LORD, nor make an offering by fire of them upon the altar unto the LORD.
Either a bullock or a lamb that hath any thing superfluous or lacking in his parts, that mayest thou offer for a freewill offering; but for a vow it shall not be accepted.
Ye shall not offer unto the LORD that which is bruised, or crushed, or broken, or cut; neither shall ye make any offering thereof in your land.” (Leviticus 22:21-24)
An animal that had a birth defect could be given as a freewill offering as it was the way God had made it. Although it was not acceptable for replacement for something a person had promised to God. Diseased or injured animals were not acceptable at all, either at the tabernacle or anywhere else.
“Neither from a stranger's hand shall ye offer the bread of your God of any of these; because their corruption is in them, and blemishes be in them: they shall not be accepted for you.” (Leviticus 22:25)
They were not to buy their offerings from non Jews because there was no way of knowing what diseases or injuries they might have contracted. Thus, such sacrifices would not be acceptable.
“And the LORD spake unto Moses, saying, When a bullock, or a sheep, or a goat, is brought forth, then it shall be seven days under the dam; and from the eighth day and thenceforth it shall be accepted for an offering made by fire unto the LORD. And whether it be cow or ewe, ye shall not kill it and her young both in one day.” (Leviticus 22:26-28)
No animal less than eight days old was acceptable as a burnt sacrifice, and in any case they were not to sacrifice both the mother and her offspring in the same day.
“And when ye will offer a sacrifice of thanksgiving unto the LORD, offer it at your own will. On the same day it shall be eaten up; ye shall leave none of it until the morrow: I am the LORD.” (Leviticus 22:29-30)
Thanksgiving sacrifices were to be completely voluntary, and the priests and people offering them were to eat them completely that same day. Nothing was to be left over or saved for the priests.
“Therefore shall ye keep my commandments, and do them: I am the LORD. Neither shall ye profane my holy name; but I will be hallowed among the children of Israel: I am the LORD which hallow you, That brought you out of the land of Egypt, to be your God: I am the LORD.” (Leviticus 22:31-33)
Every effort was to be made to show respect toward God, and appreciation for his delivering them from slavery in Egypt. By demonstrating such respect, their children and grandchildren would learn to show similar respect.