The night before His crucifixion, the Lord had a last Supper with the Disciples, one of whom was to betray Him for 30 silver dollars. The Lord's Supper was a yearly feast celebrated by the Jews before Passover, a memorial of their leaving Egypt by the help of the Lord. A blameless lamb was to be killed to mark the house of God's Elect with blood at the door, so the Angel of the Lord would save their firstborn.
"And the blood shall be to you for a token upon the houses where ye are: and when I see the blood, I will pass over you, and the plague shall not be upon you to destroy you, when I smite the land of Egypt." - Exodus 12:13
This lamb was a sign pointing to the Lamb of God, to Jesus, now having His day before He was crucified under Pilate.
Now when the even was come, he sat down with the twelve. And as they did eat, he said, Verily I say unto you, that one of you shall betray me. And they were exceeding sorrowful, and began every one of them to say unto him, Lord, is it I? And he answered and said, He that dippeth his hand with me in the dish, the same shall betray me. The Son of man goeth as it is written of him: but woe unto that man by whom the Son of man is betrayed! it had been good for that man if he had not been born. Then Judas, which betrayed him, answered and said, Master, is it I? He said unto him, Thou hast said.And as they were eating, Jesus took bread, and blessed it, and brake it, and gave it to the disciples, and said, Take, eat; this is my body. And he took the cup, and gave thanks, and gave it to them, saying, Drink ye all of it; For this is my blood of the new testament, which is shed for many for the remission of sins. But I say unto you, I will not drink henceforth of this fruit of the vine, until that day when I drink it new with you in my Father's kingdom.And when they had sung an hymn, they went out into the mount of Olives.Matthew 26:20-30 KJV