Can you provide the specific Sanskrit verse from the Gita that was the subject of discussion between Sai Baba and Nana, and what was the common understanding of its meaning?

The verse at the heart of the 'Sai-Nana dialogue' is from the Gita, specifically verse 4.34. Chapter 39 quotes the original Sanskrit: "Tadviddhi pranipatena, pariprashnena sevaya | Upadeksyanti te jnanam, jnaninastattvadarsinah." According to the source, the commonly accepted meaning, which Nana Chandorkar initially explained, is that one can attain true knowledge by approaching a Guru with prostration, sincere questioning, and dedicated service. The wise ones who have perceived the ultimate truth will then impart that knowledge to the deserving disciple.