Can you provide the specific Sanskrit verse from the Gita that Nana and Baba discussed, along with its traditional meaning?

Certainly. The verse in question is from the Bhagavad Gita, and Chapter 39 quotes it directly to aid the reader's understanding. The original Sanskrit verse is: "Tadviddhi pranipatena, pariprashnena sevaya | Upadeksyanti te jnanam, jnaninastattvadarsinah ||44||." According to the explanation provided by Nana Chandorkar, who was an expert in various commentaries, the accepted meaning is that one can attain knowledge by approaching the wise. Specifically, he explained that it is through prostration (pranipatena), respectful inquiry (pariprashnena), and service (sevaya) that the wise ones, who have perceived the ultimate truth, will impart their knowledge to a seeker.