THE PASSOVER, what it means?

Luke 22: 1 - Now the feast of the Unleavened Bread drew near, which is called the PASSOVER. (Exodus12: 40-42 The time that the people of Israel dwelt in Egypt was 430 years. And at the end of 430 years, on that very day, all the hosts of the Lord went out of Egypt. It was a night of watching by the Lord, to bring them out of the land of Egypt; so this same night is a night of watching kept to the Lord by all the people of Israel throughout their generations).
2 - And the chief priests and the scribes were seeking how to put Jesus to death; for they feared the people.
3-5 - Then Satan entered into Judas called Iscariot, who was of the number of the 12; Judas called Iscariot went away and conferred with the chief priests and captains how he might betray Jesus to them. And they were glad, and engaged to give him money.
6 - So he agreed, and sought an opportunity to betray Jesus to them in the absence of the multitude.
7 - Then came the day of Unleavened Bread, on which the passover lamb had to be sacrificed.
(Exodus 12: 21-23 Then Moses called all the elders of Israel, and said to them, "Select lambs for yourselves according to your families, and KILL THE PASSOVER LAMB. Take a bunch of hyssop and dip it in the blood which is in the basin, and touch the lintel and the two doorposts with the blood which is in the basin; and none of you shall go out of the door of his house until the morning. For the Lord will PASS THROUGH to slay the Egyptians; and when He sees the blood on the lintel and on the two doorposts, the Lord will PASS OVER the door, and will not allow the destroyer to enter your houses to slay you).
PASSOVER commemorates the DELIVERANCE of the Israelites from Egypt and the PASSING OVER of their FIRSTBORN when the Lord destroyed the firstborn of Egypt.
The head of the family was responsible for the slaying of the lamb at each home. The partakers ate in a standing position, their hips girded so their robes would not impede walking, staff in hand, sandals on to be ready for a long journey over rough ground.
At midnight all the firstborn of the Egyptians were slain from the house of the Pharaoh himself to the firstborn of the prisoner, any male firstborn one in the household under the head as well as the male firstborn of animals that was involve.
Numbers 8: 14-19 Thus you (Moses) shall separate the Levites from among the people of Israel, and the Levites shall be mine. And after the Levites shall go in to do service at the tent of meeting, when you have cleansed them and offered them as a wave offering.
For they are wholly given to me from among the people of Israel; instead of all that open the womb, the first-born of all the people of Israel, I have taken them for myself. For all the first-born among the people of Israel are mine, both of man and of the beast; ON THE DAY THAT I SLEW ALL THE FIRST-BORN IN THE LAND OF EGYPT I consecrated them for myself, and I have taken the Levites instead of all the first-born among the people of Israel.
Exodus 12: 14-17 "This day shall be for you a Memorial Day, and you shall keep it as a feast to the Lord; throughout your generations you shall observe it as an ORDINANCE FOREVER.