Can you explain the analogy of the River Ganges presented in the beginning of Chapter 47?

Chapter 47 uses a poignant analogy involving the River Bhagirathi, or Ganges, to illustrate the purifying power of saints. The text explains that while the river cleanses the world by washing away its impurities, the river itself becomes soiled. To wash away its own accumulated sins, the river longs for the dust from the feet of saints. This metaphor, as detailed in Chapter 47, emphasizes that the spiritual purity of saints like Sai is so great that even a sacred entity like the Ganges seeks their presence for its own deliverance and purification.