The last three days of Holy Week are referred to as the Easter or Sacred Triduum (Triduum Sacrum), the three-part drama of Christ's redemption: Holy Thursday, Good Friday and Holy Saturday.
Holy Thursday is also known as "Maundy Thursday." The word maundy comes from the Latin word mandatum (commandment) which is the first word of the Gospel acclamation:
Mandátum novum do vobis dicit Dóminus, ut diligátis ínvicem, sicut diléxi vos. "I give you a new commandment: Love one another as I have loved you." (John 13:34)
These are the words spoken by our Lord to His apostles at the Last Supper, after He completed the washing of the feet.
“I tell you the truth, one of you will betray Me.” They were very sad and began to say to Him one after the other, “Surely not I, Lord?” Jesus replied, “The one who has dipped his hand into the bowl with Me will betray Me. The Son of Man will go just as it is written about him. But woe to that man who betrays the Son of Man! It would be better for him if he had not been born.” Then Judas, the one who would betray Him, said, “Surely not I, Master?” Jesus answered, “Yes, it is you.”
While they were eating, Jesus took bread, gave thanks and broke it, and gave it to His disciples, saying, “Take and eat; this is My body.” Then He took the cup, gave thanks and offered it to them, saying, “Drink from it, all of you. This is My blood of the covenant, which is poured out for many for the forgiveness of sins. I tell you, I will not drink of this fruit of the vine from now on until that day when I drink it anew with you in My Father’s kingdom.”
Then one of the Twelve — the one called Judas Iscariot — went to the chief priests and asked, “What are you willing to give me if I deliver Him over to you?” So they counted out for him thirty pieces of silver. From then on Judas watched for an opportunity to hand Him over.
Then Jesus went with His disciples to a place called Gethsemane, and He said to them, “Sit here while I go over there and pray.” He took Peter and the two sons of Zebedee along with Him, and He began to be sorrowful and troubled. Then He said to them, “My soul is overwhelmed with sorrow to the point of death. Stay here and keep watch with Me.”
Going a little farther, He fell with His face to the ground and prayed, “My Father, if it is possible, may this cup be taken from Me. Yet not as I will, but as you will.”
Then he returned to His disciples and found them sleeping. He asked Peter, “Watch and pray so that you will not fall into temptation. The spirit is willing, but the flesh is weak.”
He went away a second time and prayed, “My Father, if it is not possible for this cup to be taken away unless I drink it, may your will be done.”
When He came back, He again found them sleeping, because their eyes were heavy. So He left them and went away once more and prayed the third time, saying the same thing.
Then He returned to the disciples and said to them, “Are you still sleeping and resting? Look, the hour has come, and the Son of Man is delivered into the hands of sinners. Rise! Let us go! Here comes My betrayer!”