The author of the Satcharitra compares Sai to the sun and moon in Chapter 50. Why are these comparisons ultimately considered inadequate?

In Chapter 50, the author, Hemadpant, attempts to describe Sai's magnificent nature through comparison but finds conventional metaphors lacking. The text explains that it is not fitting to compare Sai to the sun, because the sun inevitably sets each day. Similarly, a comparison to the moon is also dismissed because the moon wanes and is not always full. Chapter 50 concludes that Sai transcends these limitations, stating that 'Sai is forever complete.' Therefore, these natural phenomena, with their inherent cycles of decline, are inadequate to capture the eternal and unwavering perfection of the Sadguru.