। ॥ २१ ॥
In plain words
Light within, light without, light turned inward, beyond even the highest — light of every light, shining by itself, the very light that is Ātma: this I am, and I am Śiva.
Close to the Sanskrit
Inner light, outer light, inward light, higher than the highest; light of lights, self-shining light, the light that is Ātma—Śiva am I.