Why did Sai Baba light lamps with water, and what happened as a result?

Sai Baba's practice of lighting many lamps in the Masjid and temples was not for a personal whim, but for the good of the people. Chapter 0 explains that he would typically get oil from local oil-men and grocers. However, one day they refused to provide him with any oil. Unfazed, Maharaj proceeded to fill the lamps with water instead and lit them with a match as usual. To the astonishment of the onlookers, who were convinced of his madness, the lamps lit instantly and continued to burn throughout the night. The impact of this miracle was profound. The people of Shirdi were amazed, surrendered to Maharaj, and apologized for having insulted and harassed him, finally realizing his divine stature as described in Chapter 0.