Who did Sai Baba instruct to feed a black dog and what was the reason?

Based on the provided texts, there appears to be a misunderstanding in the question, as there is no mention of Sai Baba instructing anyone to feed a black dog. However, Chapter 0 does recount a story about a devotee named Kashiram who was advised by a different saint, Janakidas Baba, to feed sugar to ants. Kashiram took this advice so seriously that he always carried a bundle of powdered sugar for this purpose. This small act of charity became a significant part of a dramatic event where he was attacked by robbers, and he fought fiercely to protect the sugar, demonstrating how dear the instruction was to him.