What is the story of Sai Baba turning water into oil to light lamps?

This event, often called the Miracle of the Lamps, is detailed in Chapter 5. Sai Baba had a great love for lighting lamps in the mosque and would collect oil daily from local grocers. One day, the grocers conspired to stop this 'nuisance' and refused to give him any oil. Baba returned quietly to the mosque, took a tin pot with a tiny bit of oil, added water, and drank it as an offering. He then filled the lamps with plain water, and to the amazement of the grocers, he lit them. The lamps burned brightly all night, causing the grocers to feel deep repentance for having lied to him.