Why did Cholkar give up sugar, and what was the vow he made to Sai Baba?

According to Chapter 15, Cholkar's livelihood depended on passing an examination to make his job permanent. In his humility, he made a vow to Sai Baba, promising that if he passed by Baba's grace, he would distribute sugar candy (khadisakhar). Although his wish was granted, he faced financial difficulties that prevented him from immediately going to Shirdi. Because of this delay in fulfilling his vow, Cholkar decided to give up sugar as a form of penance, even drinking his tea without it, until he could complete his promised offering at Baba's feet.