How did Sai Baba manage to light the lamps in the mosque when the shopkeepers refused to provide him with oil?

This event, detailed in Chapter 5, is known as the miracle of the lamps. When the grocers conspired to stop giving Sai Baba oil, he returned to the mosque with his tin pot which contained a minuscule amount of oil. He poured water into the pot, drank the mixture as an offering, and then filled the lamps with plain water. He proceeded to light the water-soaked wicks, and to the astonishment of the watching grocers, the lamps burned brightly throughout the entire night. This miraculous event caused the grocers to feel deep repentance for having lied to Baba and causing him trouble.