How did Sai Baba seemingly test a devotee named Karnik's resolve in Nashik?

According to Chapter 33, a devotee named Karnik was on a journey to Nashik when he had an unexpected encounter at the temple of Kala Rama. While he was there for Darshan, the saint Narsing Maharaj suddenly got up from amidst his followers, grabbed Karnik's wrist, and demanded, "Give my Rupee." Karnik felt as if Sai Baba himself was accepting the offering and gave the Rupee with great joy. The text suggests this was a test of faith and acting on one's initial good impulse, noting that the Rupee was taken by force, which could have caused hesitation, but Karnik's devotion remained firm.