Can you explain the analogy of the River Ganges that is used in Chapter 47?

Chapter 47 uses a powerful analogy involving the River Bhagirathi, also known as the Ganges, to illustrate the supreme purity of saints like Sai. The text posits that while the Ganges purifies the world by washing away people's sins, she herself becomes soiled by this process. To cleanse herself of these accumulated impurities, the river desires the dust from the feet of saints. As described in Chapter 47, the Ganges knows that without the touch of a saint's feet, there is no deliverance from her own burden of sins. This metaphor elevates saints to a position of ultimate purity, suggesting their spiritual power is sought even by sacred entities.