Why did the grocers refuse to give Baba oil, and how did they react to the miracle that followed?

According to Chapter 5, the grocers refused to give Sai Baba oil because he had been acquiring it for free every day, and they developed a "wicked idea" in their minds, viewing his requests as a nuisance they wanted to stop. After they refused him and he proceeded to light the lamps with water, their reaction was one of shock and repentance. The text states they "put their fingers in their mouths" in amazement. They realized that by speaking an untruth, they had sinned and given Baba needless trouble. This recognition of Baba's power and their own wrongdoing caused them to tremble and feel deep regret.