Verse 23

उपशशाम शनैर्दिवसैरसौकतिपयैः स्वपदे विमलात्मनि ।तरुरसः शरदन्त इवामलेरविकरौजसि जन्मदशातिगः

In plain words

He, who had gone beyond the very condition of birth, grew still, gradually, over a few days, in his own stainless state -- like the sap of a tree, at autumn's end, in the clear, potent rays of the sun.