What was Cholkar's vow regarding sugar, and why was it so significant?

Cholkar's vow was to visit Shirdi, but due to financial difficulties described as the 'threshold-ghat' (home expenses), he was delayed. As a personal penance during this waiting period, he vowed to avoid sugar, treating it as an 'inedible substance.' As Chapter 15 recounts, he even drank his tea without any sugar. The significance of this private act of devotion was revealed when he finally reached Shirdi. Sai Baba's specific instruction to give him tea 'well-filled with sugar' showed that this secret, personal sacrifice was known and acknowledged by Baba, validating Cholkar's devotion and penance.