On Holy Thursday, the Mass of the Lord’s Supper is held in the evening and begins the Paschal Triduum.
This Mass commemorates the institution of the Eucharist and the priesthood, rooted in Christ’s commands to “love one another” (Jn 15:17) and to “do this in memory of me.” (Lk 22:19) To this end, many priests will perform the optional ritual of the washing of feet, which imitates the example of Christ who humbled himself to wash the feet of his disciples at the Last Supper.
At the end of this Mass, the Eucharist is carried by the priest in solemn procession through the church until it arrives at a special place of repose where the faithful are encouraged to spend time in adoration before the Blessed Sacrament. Meanwhile, the altar in the church is stripped bare and crosses are veiled or removed from the sanctuary.