The story of Sai telling someone to feed a black dog is a famous one. Based on the provided text, who was this person and what was the outcome?

Contrary to the premise of the question, the provided information from Chapter 40 does not contain the story about Sai Baba telling someone to feed a black dog. The narrative focuses on a different incident involving a devotee named Dev. Dev held an Udyapan ceremony and invited Baba, who promised to attend. Baba arrived in the guise of a Sanyasi with two others, but Dev failed to recognize him and felt let down. According to Chapter 40, Baba later clarified the situation to Jog, emphasizing that he always keeps his word. Dev, upon learning the truth, felt immense regret for his failure to perceive Baba's presence.