Purport

Continuing from earlier Shloka, Bhagvan Shri Krishna affirms, there is nothing a good purifier for the soul as the Knowledge. A person who attains the true knowledge of self gets purified, as he sees the reality of everything, able to differentiate himself from the delusion of the material world. His all faults are then automatically removed. He attains the absolute state of tranquillity.

In the same Shloka Bhagvan Shri Krishna also explained how to attain that state of knowledge. One who with pure intention work with awareness to know the truth, engages himself in the constant practice of yoga and meditation, is able to achieve the state of knowledge in due course of time, depending upon his efforts. His efforts might be to have undivided devotion for God, engaging himself in studies of scriptures, engaging in strict yoga and meditation or getting knowledge from enlightened guru by offering selfless service.