The Buddha contrasts the misdirected and well-directed mind, and explains the importance of directing the mind.

The Buddha uses the gradual purification of gold as a metaphor for mental cultivation through meditation. Just as a goldsmith removes coarse, medium, and subtle impurities until the gold is workable and radiant, a meditator abandons defilements in stages. This gradual refinement leads to deep collectedness of mind, forming the foundation for supernormal abilities and, ultimately, liberation.