A lot vs. Alot: 9 Grammatical Pitfalls
Thursday before Easter, mid-15c., from Middle English maunde "the Last Supper," also "ceremony of washing the feet," from Old French mandé, from Latin mandatum "commandment" (see mandate); said to be so called in reference to the opening words of the church service for this day, Mandatum novum do vobis "A new commandment I give unto you" (John xiii:34), words supposedly spoken by Jesus to the Apostles after washing their feet at the Last Supper.
the Thursday before Easter, observed in commemoration of Jesus Christ's institution of the Eucharist. The name is taken from an anthem sung in Roman Catholic churches on that day: "Mandatum novum do vobis" ("a new commandment I give to you"; John 13:34). In the early Christian church the day was celebrated with a general communion of clergy and people. At a special mass the bishop consecrated the holy oils in preparation for the anointing of the neophytes at the Baptism on Easter night. Since 1956 Maundy Thursday has been celebrated in Roman Catholic churches with a morning liturgy for the consecration of the holy oils for the coming year and an evening liturgy in commemoration of the institution of the Eucharist, with a general communion. During the evening liturgy the hosts are consecrated for the communion on Good Friday (when there is no liturgy), and the ceremony of the washing of feet is performed by the celebrant, who ceremonially washes the feet of 12 men in memory of Christ's washing the feet of his disciples. Eastern Orthodox churches also have a ceremony of foot washing and blessing of oil on this day.