I read that Sai Baba once told someone to feed a black dog as a test. Can you explain the details of this event and who was involved?

The source material from Chapter 40 does not contain any story about Sai Baba asking a devotee to feed a black dog. The central event discussed is about Baba's promise to a devotee named Dev to attend his Udyapan ceremony. Baba fulfilled this promise by appearing in the form of a Sanyasi, along with two companions, and having a meal. According to Chapter 40, Dev did not recognize Baba in this guise and felt disappointed, believing Baba had not come. Baba later clarified through another devotee, Jog, that he had kept his promise, stating, "I said I would come with two others, and I went with two others."