What is the meaning behind the swan and milk analogy presented in Chapter 17?

In Chapter 17, the analogy of the swan (Maral) drinking only pure milk from a mixture of milk and water is a metaphor for spiritual discrimination. The chapter explains that just as the swan can separate the two liquids, a wise and fortunate person can distinguish between the path of Shreya (wisdom) and Preya (worldly pleasure), even though they are often blended in life. This ability allows them to choose only Shreya, the path of salvation, and reject the allure of worldly attachments. As Chapter 17 suggests, this act of discernment is the essence of true human effort (Purushartha) and a characteristic of those who are courageous and intelligent.