What mistake did Babasaheb Tarkhad make during the worship, and what was his immediate reaction?

The mistake Babasaheb Tarkhad made was forgetting to offer the daily Naivedya. Chapter 9 recounts that one day, being busy with his business as a chief officer at a large mill, he forgot to offer the piece of sugar candy during the morning worship. He only realized his error at mealtime when he did not receive the sugar candy as 'Prasad'. His reaction was one of extreme remorse and repentance. The text describes him being "filled with remorse," bowing to Sai's image with tearful eyes, and calling the mistake a "great sin." He felt he had failed and pleaded for forgiveness, immediately sending a letter to his son in Shirdi to ask for Sai's mercy.