Chapter 47 uses an analogy involving the River Ganges. What is this analogy and what point is it trying to make about saints like Sai?

Chapter 47 employs a powerful analogy of the River Ganges to highlight the purifying power of saints. The text explains that while the Ganges washes the feet and sins of the world, she herself becomes soiled with these accumulated impurities. To cleanse herself, the river desires the dust from the feet of saints. As Chapter 47 explains, the Ganges knows that without the touch of a saint's feet, there is no deliverance from her own accumulated sins. This metaphor powerfully illustrates the supreme holiness and purifying capability of saints like Sai, suggesting their spiritual power is so immense that even a sacred entity like the Ganges seeks them out for purification.