What was the specific promise Babasaheb Tarkhad made to his son regarding Sai's worship, and how did he conduct the ritual initially?

The specific promise Babasaheb Tarkhad made to his son is detailed in Chapter 9. He solemnly vowed that "Without offering Naivedya to Sai, no one should consume food at home." He assured his son that he would personally carry out this duty every day. Upon his son's departure for Shirdi, Babasaheb Tarkhad began performing the worship with great sincerity. He would bathe in the early morning and then pray before Sai's image, asking that his service be as pure as his son's and that no mistakes would occur. His daily ritual involved offering a piece of sugar candy as Naivedya, a rule he followed diligently until the day he unfortunately forgot.