What was the spiritual significance of Sai's instruction to feed a black dog, according to the provided text?

The provided source material does not contain any story or mention of Sai Baba advising someone to feed a black dog, so there is no spiritual significance discussed. The excerpts from Chapter 41 are focused entirely on a different devotee's challenge. They detail the struggles of Balasaheb Deo, who greatly desired to read the Dnyaneshwari but found himself unable to do so consistently. According to Chapter 41, his frustration led him to make a vow to only read the sacred text if Sai Baba personally commanded him to do so, a testament to his faith and his difficulty.