Each thing tends to move towards its own nature. I always desire happiness which is my true nature. My nature is never a burden to me. Happiness is never a burden to me, whilst sorrow is.
Just as a stone, a tree, a straw, grain, a mat, a cloth, a pot, and so on, when burned, are reduced to earth (from which they came), so the body and its sense organs, on being burned in the fire of Knowledge, become Knowledge and are absorbed in Brahman, like darkness in the light of the sun.