I heard Das Ganu was writing a book and got stuck. What was the project, and what was the specific problem he faced?

Chapter 20 explains that Das Ganu was working on a commentary called the "Ishavasya-Bhavartha-Bodhini." His goal was to make the profound Ishavasya Upanishad accessible to those who were not familiar with the Sanskrit language by explaining its meaning word for word in simple Prakrit Ovi verses. However, while he managed a literal translation, he found that he could not grasp the deep, internal secret of the Upanishad. This lack of understanding caused him to feel no joy in his work, which prompted him to take his doubt to the feet of his Satguru, Sai Baba, in Shirdi.