Why did the grocers decide to stop giving Baba oil, and what was the ultimate consequence of their actions?

As detailed in Chapter 5, Sai Baba had a great love for lighting lamps and would daily go to the local grocers to beg for oil. After some time, the grocers grew tired of this and, with a "wicked idea," conspired to stop what they considered a "nuisance." They collectively refused to give him oil when he came to ask. The consequence of their action was not what they expected. Baba performed a miracle, lighting the lamps with water. Seeing the lamps burn all night without oil, the grocers were astounded and filled with remorse, realizing they had sinned by lying to a holy man.