What is the spiritual principle regarding a disciple's acceptance of prasad from a Guru, as explained in the text?

The scripture in Chapter 38 discusses a profound spiritual principle concerning the master-disciple relationship. It states that when a Guru personally gives Prasad, if the disciple harbors any doubt about whether the food is edible or inedible, that disciple suffers a form of 'spiritual suicide' and heads towards a downfall. This concept is introduced to explain why devotees were expected to accept what Baba gave them without question. The text notes that Baba Himself would use jokes and humor, like the incident with Dada Kelkar, to make His devotees experience and understand this deep principle of unwavering faith in the Guru's wisdom and command.