Dvav Imau Purushau Loke

Krishna now introduces a new framework — two categories of existence. The first is kshara, the perishable. Everything that changes, everything that comes and goes — all bodies, all objects, all forms and names — this is kshara. The second is akshara, the imperishable. That which does not change, does not decay, does not fluctuate.

The imperishable is called 'kootastha' — like an anvil. A blacksmith places an anvil on a rock and hammers metal upon it. The metal bends and shapes, but the anvil stays firm. Everything around the akshara changes; the akshara itself does not.

Understanding this division brings clarity. What we see, hear, and touch in daily life — that is kshara. What remains steady beneath all of it — unchanged by birth, death, joy, or sorrow — that is akshara.

Shlokas 15.16 through 15.18 form the philosophical summit of this chapter. First comes the distinction between kshara and akshara (15.16), then the revelation of Purushottama who transcends both (15.17), and finally the significance of the name Purushottama (15.18). This triad gives the chapter its title: Purushottama Yoga. The term 'kootastha' appears elsewhere in the Gita as well (6.8, 12.3).