Matthew 27:3-7

Then Judas, which had betrayed him, when he saw that he was condemned, repented himself, and brought again the thirty pieces of silver to the chief priests and elders, saying, I have sinned in that I have betrayed the innocent blood. And they said, What is that to us? see thou to that. And he cast down the pieces of silver in the temple, and departed, and went and hanged himself. And the chief priests took the silver pieces, and said, It is not lawful for to put them into the treasury, because it is the price of blood. And they took counsel, and bought with them the potter's field, to bury strangers in.