John 13:25

So, John leaned over close to Jesus and asked Him, "Lord, who is it?"

John 21:20

Peter turned around and saw the disciple whom Jesus loved [i.e., probably the apostle John] following [along behind him]. This was the same disciple who had leaned over close to Jesus at the [Passover] meal and asked Him, "Lord, who is it that will turn you over [to the Jewish authorities]?"

Treasury of Scripture Knowledge

Summary

He then lying on Jesus' breast saith unto him, Lord, who is it?

General references

Bible References

General references

Matthew 26:22
And they were extremely grieved, and each one of them began saying to Him, "Am I the one, Lord?"
Luke 22:23
So, the apostles began discussing among themselves which one of them would do such a thing.