John 13:11 KJV

In context

10 Jesus saith to him, He that is washed needeth not save to wash his feet, but is clean every whit: and ye are clean, but not all.

11 For he knew who should betray him; therefore said he, Ye are not all clean.

12 So after he had washed their feet, and had taken his garments, and was set down again, he said unto them, Know ye what I have done to you?

Read all of John 13