After the shopkeepers refused to give Sai Baba oil, how did they react to witnessing him light the lamps with water?

The shopkeepers' reaction was one of utter amazement that quickly turned to deep repentance. Chapter 5 describes them watching to see what Baba would do without oil. When they saw the water-filled lamps burning, they were so shocked they "put their fingers in their mouths." They immediately recognized their wrongdoing, admitting to themselves that they had lied to Baba. The fact that the lamps burned all night without a drop of oil made them tremble, feeling unworthy of Sai's grace. They were overcome with repentance for having sinned and given Baba needless trouble.