What was Balasaheb Deo's primary spiritual struggle as described in these passages, and what unique vow did he make because of it?

Balasaheb Deo's main spiritual struggle was his inability to consistently read the Dnyaneshwari, despite a great desire to do so. Chapter 41 explains that while he could read other texts like the Bhagavad Gita regularly, some obstacle would always arise when he tried to read the Dnyaneshwari. Even taking a three-month leave from work didn't help, as doubts would fill his heart, making the reading superficial. Feeling distressed by his failure to read even five verses daily, he made a unique vow. He resolved with firm faith that he would only begin reading the Dnyaneshwari when Sai Baba himself gave him a direct order and instilled the necessary love for the text in his heart.