Final answer:
At the beginning of the Last Supper, Jesus washed the disciples' feet. This act is an example of humility and service. The Last Supper is also notable for Jesus instituting the Eucharist and for its significant representations in art history, including Leonardo da Vinci's dramatic portrayal.
Step-by-step explanation:
Near the beginning of the Last Supper, according to John 13:2-15, the Lord Jesus washed the feet of the disciples. This event, depicted in the mosaic at Hosios Loukas Monastery, is a symbolic act of humility and service, with Jesus stating, "If I, your Lord and Teacher, have washed your feet, you also ought to wash one another's feet. For I have set you an example" (John 13:14-15). The Last Supper is central to Christian tradition, not only for the foot washing but also as the moment when Jesus instituted the Eucharist, as recorded in Matthew 26:20-29 where Christ blessed bread and wine, giving them to his apostles as his body and blood.
This moment is not only significant in religious context but also in art history. Leonardo da Vinci's The Last Supper captures the emotional response of the apostles as Jesus announces that one will betray him. Rather than following the usual tradition of depicting Judas separately, Leonardo places him on the same side as Christ and the other apostles, incorporating an element of psychological drama into the artwork.