God burns Aaron's sons to death
1 And Nadab and Abihu, the sons of Aaron, took either of them his censer, and put fire therein, and put incense thereon, and offered strange fire before the LORD, which he commanded them not.
2And there went out fire from the LORD, and devoured them, and they died before the LORD.
Aaron's sons, Nadab and Abihu, offered strange fire in front of God, which he commanded them not to do.
So God burned them to death. 
3 Then Moses said unto Aaron, This is it that the LORD spake, saying, I will be sanctified in them that come nigh me, and before all the people I will be glorified. And Aaron held his peace.
Moses said to Aaron,
This is what God said,
I will be sanctified by those that are near me, and I will be glorified by everyone.
And Aaron watched in silence as God burned his sons to death.
4 And Moses called Mishael and Elzaphan, the sons of Uzziel the uncle of Aaron, and said unto them, Come near, carry your brethren from before the sanctuary out of the camp.
5 So they went near, and carried them in their coats out of the camp; as Moses had said.
Moses called his cousins, Mishael and Elzaphan, and said to them,
Carry the burned bodies outside the camp.
So they carried the bodies in their coats outside the camp.
6 And Moses said unto Aaron, and unto Eleazar and unto Ithamar, his sons, Uncover not your heads, neither rend your clothes; lest ye die, and lest wrath come upon all the people: but let your brethren, the whole house of Israel, bewail the burning which the LORD hath kindled.
Moses said to Aaron and his two remaining sons, Eleazar and Ithamar,
Don't mourn the death of Nadab and Abihu by uncovering your head or tearing your clothes -- or God will kill you, along with everyone else.
Let your relatives and the people mourn their deaths.
7 And ye shall not go out from the door of the tabernacle of the congregation, lest ye die: for the anointing oil of the LORD is upon you. And they did according to the word of Moses.
Don't go out the door of the tabernacle, or you will die (because you have been anointed by God).
So they did what Moses said.
God's instructions to priests
8 And the LORD spake unto Aaron, saying,
9Do not drink wine nor strong drink, thou, nor thy sons with thee, when ye go into the tabernacle of the congregation, lest ye die: it shall be a statute for ever throughout your generations:
10 And that ye may put difference between holy and unholy, and between unclean and clean;
God said to Aaron,
You and your sons must not drink wine or strong alcoholic beverages when you go into the tabernacle, or you will die. 
This is a statute forever.
11 And that ye may teach the children of Israel all the statutes which the LORD hath spoken unto them by the hand of Moses.
Teach the Israelites all of the statutes I have spoken to Moses.
12 And Moses spake unto Aaron, and unto Eleazar and unto Ithamar, his sons that were left, Take the meat offering that remaineth of the offerings of the LORD made by fire, and eat it without leaven beside the altar: for it is most holy:
13 And ye shall eat it in the holy place, because it is thy due, and thy sons' due, of the sacrifices of the LORD made by fire: for so I am commanded.
Moses said to Aaron and his remaining sons,
Eat the meat offerings without leaven. It is most holy.
Eat it in the holy place. You deserve it.
That's what I was commanded.
14 And the wave breast and heave shoulder shall ye eat in a clean place; thou, and thy sons, and thy daughters with thee: for they be thy due, and thy sons' due, which are given out of the sacrifices of peace offerings of the children of Israel.
15The heave shoulder and the wave breast shall they bring with the offerings made by fire of the fat, to wave it for a wave offering before the LORD; and it shall be thine, and thy sons' with thee, by a statute for ever; as the LORD hath commanded.
You and your sons and your daughters shall eat the wave breast and heave shoulder in a clean place.
You deserve it.
It's a statute forever, as God commanded.
16 And Moses diligently sought the goat of the sin offering, and, behold, it was burnt: and he was angry with Eleazar and Ithamar, the sons of Aaron which were left alive, saying,
17 Wherefore have ye not eaten the sin offering in the holy place, seeing it is most holy, and God hath given it you to bear the iniquity of the congregation, to make atonement for them before the LORD?
Moses couldn't find the sin offering goat.
When he found out that it have been burned, he was angry with Aaron's sons, and said,
Why didn't you eat the sin offering in the holy place, seeing that it is most holy?
18 Behold, the blood of it was not brought in within the holy place: ye should indeed have eaten it in the holy place, as I commanded.
You should have eaten it in the holy place, as I commanded.
19 And Aaron said unto Moses, Behold, this day have they offered their sin offering and their burnt offering before the LORD; and such things have befallen me: and if I had eaten the sin offering to day, should it have been accepted in the sight of the LORD?
20 And when Moses heard that, he was content.
Aaron said to Moses,
What if I had eaten the burnt offering? Would it have been accepted by God?
And when Moses heard that, he was content.