Nothing scrubs the heart like understanding; this verse promises that honestly facing what happened is itself the beginning of becoming clean.
न हि ज्ञानेन सदृशं पवित्रमिह विद्यते। तत्स्वयं योगसंसिद्धः कालेनात्मनि विन्दति।।4.38।।
na hi jñānena sadṛiśhaṁ pavitramiha vidyate tatsvayaṁ yogasansiddhaḥ kālenātmani vindati
Verily there exists nothing in this world purifying like knowledge. In good time, having reached perfection in Yoga, one realises that oneself in one's own heart.
— Swami Swarupananda