Why does the author of Chapter 50 find it inadequate to compare Sai Baba to the sun or the moon?

In Chapter 50, the author, Hemad, contemplates how to describe Sai's greatness and concludes that common celestial comparisons fall short. He states that it is not fit to compare Sai to the sun, for the sun inevitably sets. Likewise, a comparison to the moon is also unsuitable because the moon wanes and is not always full. In contrast to these transient and cyclical natural phenomena, the author asserts that 'Sai is forever complete.' This highlights Sai's eternal, unchanging, and perfect nature, which transcends the limitations of the physical world.