Later, Jesus and his disciples were in an upper room where they had gone to celebrate the important Jewish Festival of 'Pesach',
(Passover), when death had passed over the Jewish households and spared the people as they escaped from exile and slavery in Egypt
(Exodus 12). This was the 'Last Supper' Jesus would eat with his disciples before he was arrested and executed.
Israel is a hot, dry land and in those days most people travelled on foot, so it was the custom to welcome visitors by washing their dusty feet. Normally a household servant did this - the lowest of the low. When Jesus invited his disciples to supper in the upper room, they were surprised by what Jesus did.
He rose from the table, took off his outer garment, and tied a towel around his waist. Then he poured some water into a basin and began to wash their feet, drying them with the towel round his waist. When he had finished, he returned to his place and asked, "Do you understand what I have done for you? You call me teacher and Lord, and rightly so, for that is what I am. Now that I, your Lord and teacher, have washed your feet, you also should wash one another's feet. I have set you an example, that you should do as I have done for you." He added, "Now I give you a New Commandment: love one another. As I have loved you, so you must love one another."
(John 13:4-5, 12-15 & 34).