Can you explain the story of the devotee who made a vow to Lord Datta and how Sai Baba reminded him of it?

A man from the Ghats, seeking a job in Goa to support his family, made a respectful vow to Lord Datta. He promised that if he secured employment, he would offer his entire first month's salary to the Lord. As Chapter 36 recounts, he was blessed with a job starting at fifteen rupees and later received promotions, but he completely forgot his vow. Sai Baba, through a seemingly unrelated story about a Brahmin, reminded the man of his past. The man later realized that the 'Dakshina' Baba was requesting was not a mere gift but a 'repayment of a debt,' a clever pretext to remind him of his old, forgotten promise to Lord Datta.