The text mentions a specific verse from the Bhagavad Gita. What is the verse and what unique interpretive point does Chapter 50 make about it?

Chapter 50 references the 34th verse from the fourth chapter of the Bhagavad Gita: "Tadviddhi pranipatena pariprasnena sevaya | upadeksyanti te jnanam jnaninastattvadarsinah ||". The unique point highlighted by the author is a linguistic and conceptual one regarding the word 'Jnana' (knowledge). The text suggests that an 'Avagraha' (a specific Devanagari symbol) can emerge before 'Jnana' in the third line, which acts as an indicator of 'Ajnana' (ignorance). This interpretation is used to argue that one must first understand and address ignorance before true knowledge can be imparted by the knowers of truth.