How did a simple mistake like forgetting to offer sugar candy lead to such extreme repentance for Babasaheb Tarkhad?

Babasaheb Tarkhad's intense repentance stemmed from the solemn promise he had made to his son. As Chapter 9 explains, he had vowed that no one would eat before Naivedya was offered to Sai. He faithfully performed this daily ritual, offering sugar candy. However, one day, being preoccupied with his business as a chief officer, he forgot. The gravity of this lapse hit him at mealtime when he didn't receive the sugar candy Prasad. He didn't see it as a simple mistake but as a "great sin" and a failure of his word. His heart was "choked with grief," and he felt he had "reached great repentance," prostrating before Sai's image with tearful eyes because he had broken a sacred vow made out of love for his son and respect for Sai.