And while they were eating, he said: "Amen I say to you, that one of you is about to betray me.
Other versions
King James Version
And as they did eat, he said, Verily I say unto you, that one of you shall betray me.English Standard Version
And as they were eating, he said, "Truly, I say to you, one of you will betray me."New International Version
And while they were eating, he said, "I tell you the truth, one of you will betray me."