Now I tell you before it come, that, when it is come to pass, ye may believe that I am he.
John 13:19
King James Version (public domain)
Traditionally attributed to John · 1st century AD · One of the twelve apostles of Jesus; the "beloved disciple"
Context
17If ye know these things, happy are ye if ye do them.
18I speak not of you all: I know whom I have chosen: but that the scripture may be fulfilled, He that eateth bread with me hath lifted up his heel against me.
19Now I tell you before it come, that, when it is come to pass, ye may believe that I am he.
20Verily, verily, I say unto you, He that receiveth whomsoever I send receiveth me; and he that receiveth me receiveth him that sent me.
21When Jesus had thus said, he was troubled in spirit, and testified, and said, Verily, verily, I say unto you, that one of you shall betray me.