What was the spiritual lesson behind Sai Maharaj demanding Dakshina from Kashiram until he faced financial ruin?

The incident with the Dakshina was a spiritual test designed to remove an obstacle from Kashiram's path. As Chapter 0 details, Kashiram felt pride in his ability to give, which is a hindrance to spiritual progress. To remove this pride, Maharaj started demanding more and more Dakshina, even forcing Kashiram to borrow money. The entire leela, or divine play, was to make Kashiram realize that he did not truly have the 'power to give.' Once he learned this lesson and his pride vanished, his financial condition improved again.