Why did Sai Baba seem to play favorites with the two men from Goa by taking money from one but not the other?

In the story of the two gentlemen from Goa, as narrated in Chapter 36 of the Shri Sai Satcharitra, Sai Baba's actions appeared partial. He specifically asked for and accepted fifteen rupees in dakshina from one man but rejected a voluntary offering of thirty-five rupees from his friend. When questioned about this by a surprised Madhavrao (Shama), Baba explained that he personally takes nothing from anyone. He stated, "Mother Masjid demands what is owed, and the giver becomes free from debt." Baba clarified that he has no family or need for wealth, but emphasized that debt, enmity, and murder are inescapable and follow a person through time, suggesting the transaction was related to a past karmic debt rather than favoritism.