Chapter 50 compares Sai to the sun and the moon. Why does the author conclude these comparisons are inadequate?

In Chapter 50, the author, Hemadpant, attempts to describe Sai Baba's eternal nature by comparing him to celestial bodies but finds the analogies lacking. He notes that it is not fitting to compare Sai to the sun, because the sun eventually sets, whereas Sai's presence is constant. Similarly, a comparison to the moon is also deemed insufficient because the moon wanes and has phases, while Sai is described as being "forever complete." These failed comparisons are used to highlight the author's point that Sai's greatness and eternal, unchanging nature are beyond worldly metaphors and are truly unfathomable.