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

In a dramatic turn of events, Judas Iscariot, once one of Jesus' trusted disciples, hit a point of no return after accepting the infamous 30 pieces of silver to betray his friend. After realizing the grave mistake he'd made—having driven Jesus into the hands of those who would crucify him—he was consumed with remorse. It's striking how this moment of horror prompts not only self-reflection, but also historical and moral consequences that echo throughout the ages.

When Judas returned the silver and hurled it at the feet of the religious leaders, he wasn’t just unloading the money; he was symbolically shedding the heavy yoke of guilt—a guilt so immense that the disciples permeated their community with a shared understanding of betrayal. The chief priests, unwilling to defile their treasury with blood money, used it instead to buy a potter’s field. But interestingly, this field became known as "Akeldama," which translates to "Field of Blood"—a fitting name forever linked to treachery.

This act holds historical significance not only for kicking off a dark chain of events in the biblical narrative but also for a profound moral lesson: the weight of sin can lead to irreversible consequences. Much as Judas attempted to reconcile with his actions, echoing sentiments of regret found in ancient texts from different cultures, the reminder remains potent—our decisions are often laden with ramifications that transcend our expectations, weaving into the broader tapestry of human experience.