What led the grocers to stop giving Baba oil, and how did this action backfire on them?

The grocers decided to stop providing oil because they grew tired of giving it away for free every day. Chapter 5 states that they developed a 'wicked idea' and conspired together, viewing Baba's daily request as a 'nuisance' that needed to stop. However, their plan backfired significantly. Their refusal prompted Baba to perform the miracle of lighting the lamps with water. This incredible display of power not only rendered their refusal pointless but also filled them with guilt and fear, causing them to repent for having lied to and troubled a divine being.