Meaning “The soul is invisible, inconceivable, unable to be changed. This wisdom shall make you, not grieve for dead.” ExplanationLord Krishna wishes to attract his attention on the minutest details. That just as the body is visible, the world is witnessed physically, the eternal soul is beyond vision of human sight. It is beyond comprehension and is inconceivable because it is deprived of the material  body . That’s why it is termed Avayakt, Achinta ,that is mind, intellect are not seen and are contemplative but the soul is not the subject of contemplation. The soul is free from vices and any deficiency.Krishna gave knowledge to Arjun, just as God gave knowledge to others in the past to keep his message intact for every generation. Lord Krishna explains Arjun, that the magnitude of the invisible soul is beyond the power of the microscope .The soul can’t be perceived or studied  by the material or scientific gadgets of modern times but by the vedic knowledge only, established by the higher authorities to confirm the stability of existence of the soul.The soul is consciousness and conscious at the same time. Heart and mind can’t be perceived but are ingrained in the very soul .  Nevertheless, the soul is invisible and inconceivable by the eyes and mind. LORD KRISHNA repeatedly mentioned the characteristics of the soul here, in order to make Arjun understand it thoroughly and come out  of the overwhelming grief, confusion and ignorance .Could still have no reason to grieve