Being constantly given to spiritual introspection, perceiving the true object of life as determined by the tenets of spiritual wisdom – all these together (beginning from verse 13.8) constitute true wisdom. Everything else is sheer ignorance.
To conclude, Krishna is stressing two qualities: (1) The seeker should consistently be given to spiritual contemplation, which should sublimate all activities and interactions during the non-meditative hours. (2) the seeker should always visualize the true goal of spiritual knowledge. It should always be a beacon light constantly shining in and through all his activities and interactions.
Krishna pronounces that all these qualities and virtues constitute true spiritual wisdom; all else is sheer ignorance. Spiritual wisdom is not just a theoretical knowledge of Brahman or the Self. True knowledge represents a complete transformation of our personality. Enlightenment must bring about an expanse, elevation and freedom.