The senses, they say, are superior; higher than the senses is the mind; higher than the mind is the intellect; and higher still than the intellect is That.
Explanation
Krishna has just told Arjuna to master the senses and destroy desire (kāma), the destroyer of knowledge. Here he lays out a ladder of ever subtler levels within a person: the senses (indriya), the mind (manas), the intellect or faculty of discernment (buddhi), and beyond them all 'That' (saḥ). Most traditional commentators take 'That' to be the self (ātman), while a few read it as desire itself, lying beyond the reach of the intellect.