The answer is: Gave them back

Matt 27:3-4 - He threw them down in front of the chief priests and elders, and being tainted money they decided they couldn't put it in the treasury and so bought a field instead in which to bury strangers

The saga of Judas Iscariot serves as a gripping chapter in the narrative of the Gospels. When Judas realized the depth of his betrayal, he returned the dirty silver coins—30 pieces, reflecting Zechariah 11:12-13, a prophecy often seen echoing in this context. Imagine the pressure weighing heavily on him, the very symbols of his disloyalty cast aside like so much filth.

How fascinating that these tainted coins couldn't enter the temple's coffers; such was the effect of conscience, marrying financial transactions with ethical decisions. The priests, though complicit in wrongdoing themselves, refused to sully sacred funds, opting instead to purchase what was known as the "Field of Blood," which, believe it or not, became a burial ground for the poor. Talk about full-circle consequences!

This field now stood as a grisly monument of shame—a stark reminder of how ambition and betrayal can lead one to act against their core values. In further relating to community and morality, Judas’s remorse highlights a pivotal teachable moment about accountability and consequences.

Interestingly, while his name wound boldly across centuries as a symbol of betrayal, the request among various scholars arises: Was his role predestined, or could different choices have unraveled a less dismal tale? Exploring topics like free will and destiny remains a tantalizing venture, embedded deeply within many spiritual contemplations where moral judgment hangs in the balance.