John 13:11

For He knew who was going to betray Him; this is why He said, "You are not all clean."

John 2:25

and needed no testimony from anyone about them, for He well knew what was in human nature.

Matthew 26:24-25

The Son of Man is going away as the Scriptures say of Him, but a curse will be on that man by whom He is betrayed. It would have been better for that man, if he had never been born!"

John 6:64-71

But there are some of you who do not trust in me." For Jesus knew from the start who they were that did not trust in Him, and who it was that was going to betray Him.

John 13:2

So Jesus, while supper was on -- although He knew that the devil had suggested to Judas Iscariot, Simon's son, to betray Him --

John 13:18

I do not mean all of you. I know whom I have chosen, but I know that the Scriptures must be fulfilled: 'The man who is eating my bread has lifted his heel against me.'

John 13:21

After saying this Jesus was deeply moved in spirit and solemnly said, "I most solemnly say to you, one of you is going to betray me."

John 13:26

Jesus answered, "It is that one to whom I give the piece of bread when I dip it in the dish." So He dipped it into the dish and took it and gave it to Judas, Simon Iscariot's son.

John 17:12

As long as I was with them, I kept them by your power which you gave me, and I protected them, and not one of them was lost, except the one who is now doomed to be lost, so that the Scripture might be fulfilled.

Treasury of Scripture Knowledge

Summary

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

Bible References

General references

John 13:18
I do not mean all of you. I know whom I have chosen, but I know that the Scriptures must be fulfilled: 'The man who is eating my bread has lifted his heel against me.'
John 2:25
and needed no testimony from anyone about them, for He well knew what was in human nature.
John 6:64
But there are some of you who do not trust in me." For Jesus knew from the start who they were that did not trust in Him, and who it was that was going to betray Him.
John 17:12
As long as I was with them, I kept them by your power which you gave me, and I protected them, and not one of them was lost, except the one who is now doomed to be lost, so that the Scripture might be fulfilled.
Matthew 26:24
The Son of Man is going away as the Scriptures say of Him, but a curse will be on that man by whom He is betrayed. It would have been better for that man, if he had never been born!"