Before the Festival of Passover, Jesus knew that his time had come to leave this world and go to the Father. Having loved his own who were in the world, he loved them fully.
Jesus and his disciples were sharing the evening meal. The devil had already provoked Judas, Simon Iscariot's son, to betray Jesus.
Jesus knew the Father had given everything into his hands and that he had come from God and was returning to God.
So he got up from the table and took off his robes. Picking up a linen towel, he tied it around his waist.
Then he poured water into a washbasin and began to wash the disciples' feet, drying them with the towel he was wearing.
When Jesus came to Simon Peter, Peter said to him, "Lord, are you going to wash my feet?"
Jesus replied, "You don't understand what I'm doing now, but you will understand later."
"No!" Peter said. "You will never wash my feet!" Jesus replied, "Unless I wash you, you won't have a place with me."
Simon Peter said, "Lord, not only my feet but also my hands and my head!"
Jesus responded, "Those who have bathed need only to have their feet washed, because they are completely clean. You disciples are clean, but not every one of you."
He knew who would betray him. That's why he said, "Not every one of you is clean."
After he washed the disciples' feet, he put on his robes and returned to his place at the table. He said to them, “Do you know what I've done for you?
You call me ‘Teacher' and ‘Lord,' and you speak correctly, because I am.
If I, your Lord and teacher, have washed your feet, you too must wash each other's feet.
I have given you an example: just as I have done, you also must do.
I assure you, servants aren't greater than their master, nor are those who are sent greater than the one who sent them.
Since you know these things, you will be happy if you do them.
I'm not speaking about all of you. I know those whom I've chosen. But this is to fulfill the scripture, The one who eats my bread has turned against me.
References for John 13:18
"I'm telling you this now, before it happens, so that when it does happen you will believe that I Am.
I assure you that whoever receives someone I send receives me, and whoever receives me receives the one who sent me."