What promise did Babasaheb Tarkhad make regarding the daily worship, and how did he eventually falter?

Babasaheb Tarkhad made a solemn promise to his son that he would continue the daily worship of Sai Baba while the son was away in Shirdi. Specifically, he vowed to offer Naivedya (a food offering) to Sai's image every day before anyone in the household consumed their food. Chapter 9 describes how he initially fulfilled this promise diligently, establishing a routine of offering a piece of sugar candy. However, he faltered one day due to being preoccupied with his business as a chief officer at a large mill. In his hurry, he completely forgot to make the offering. He only realized his mistake later when he sat down for his meal and the customary prasad was missing from his plate.