The text mentions that even a 'wise' person can be deluded. How does this happen, and what is the prescribed solution to overcome this delusion?

Chapter 50 explains that a person, even if considered 'wise', can be deluded and not know their own welfare if their mind is fixed on wealth, luxury, wife, and sons. As long as such a person is without devotion, their knowledge is covered by ignorance. This ignorance manifests from doubt (vikalpa), which can corrupt knowledge just as a drop of fermented gruel spoils a large pot of milk. The text is clear that this doubt and the resulting ignorance cannot be removed without a Guru. The solution is to first understand ignorance and, with a Guru's help, remove it to purify the mind, which then allows infinite knowledge to manifest.