Maundy Thursday commemorates the Last Supper of Jesus Christ with his twelve Disciples. During this supper, the Lord instituted the Eucharist, the Sacrament at the heart of every Mass. The Eucharist is the “source and summit of the Christian life”.
[26] Now as they were eating, Jesus took bread, and after blessing it broke it and gave it to the disciples, and said, “Take, eat; this is my body.” [27] And he took a cup, and when he had given thanks he gave it to them, saying, “Drink of it, all of you, [28] for this is my blood of the covenant, which is poured out for many for the forgiveness of sins.
Washing of Feet
In many parishes on Maundy Thursday, the priest will wash the feet of members of the congregation during the Mass of the Lord's Supper.
[14] If I then, your Lord and Teacher, have washed your feet, you also ought to wash one another’s feet. [15] For I have given you an example, that you also should do just as I have done to you.