6The chief priests picked up the coins and said, “It is against the law to put this into the treasury, since it is blood money.” 7So they decided to use the money to buy the potter’s field as a burial place for foreigners. 8That is why it has been called the Field of Blood to this day. 9Then what was spoken by Jeremiah the prophet was fulfilled: “They took the thirty pieces of silver, the price set on him by the people of Israel, 10and they used them to buy the potter’s field, as the Lord commanded me.”
Matthew 27:6 - 10
ESV - 6 But the chief priests, taking the pieces of silver, said, "It is not lawful to put them into the treasury, since it is blood money. 7 So they took counsel and bought with them the potter's field as a burial place for strangers.
For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
Acts 1:18 King James Version (KJV)
18 Now this man purchased a field with the reward of iniquity; and falling headlong, he burst asunder in the midst, and all his bowels gushed out.
While the literary style might seem a bit weird to us, the purchase of the field would have been ascribed to Judas since it was his money, even though the actual purchase was conducted by the chief priests.
Think of what happens if a rich person dies and has a sum of money set aside for charity, but leaves it up to the executor how to distribute it. Even if the executor conducts the purchase of a park for a neighborhood, the purchase is ascribed to the dead patron.