13.13 ज्ञेयम् has to be known, यत् which, तत् that, प्रवक्ष्यामि (I) will declare, यत् which, ज्ञात्वा knowing, अमृतम् immortality, अश्नुते (one) attains to, अनादिमत् the beginningless, परम् supreme, ब्रह्म Brahman, न not, सत् being, तत् that, न not, असत् nonbeing, उच्यते is called.Commentary: The Lord praises that which ought to be known (Para Brahman) in order to create in Arjuna (or any hearer) an intense desire to know It.Brahman cannot be expressed in words like being or nonbeing, because Brahman does not belong to any class or genus like a Brahmana, cow or horse. It has no ality like whiteness, blackness, etc. It has no relation or connection with anything else, because It is one without a second. It is no object of any sense. It is beyond the reach of the mind and the senses. It is actionless. It is the great transcendental and unmanifested Absolute. It is always the witnessing subject in all objects.The Vedas emphatically declare that Brahman is without attributes, activity, attachment or parts.In chapter IX. 19 it was stated that He is the being and also the nonbeing. It is now stated that He is neither being nor nonbeing. This would seem to the readers to be a contradiction in terms but it is not so. Though the manifest (perishable) and the unmanifest (imperishable) universe are both forms of Brahman, He is beyond both these. (Cf.VII.2XV.16,17and18)