In plain words
I have told you what Ṛta means. Mind, speech and action: these three must be one. To say what one thinks, to do what one says. Today saying and doing become one to some extent, but thought does not become one with them. For some, thought is one thing, saying another, and doing something else again. Each one goes its own different way. That is why Ṛta has wholly withered in humanness. But there is a reason for this. Though the Buddhi is very pure, we are letting some impurity into it. What is this Buddhi like? It is like the chimney, a jar, set over a lamp! This chimney is quite clean. The flame burning inside shines brightly. But after a while, a pitch darkness spreads. What is the reason for this darkness? The smoke that gathers in the chimney dirties it to some extent. Not only that: outside the chimney too, some dust and grime settle on it and block this light. When the soot inside and the dust and grime outside are wiped away, the light stays as bright as ever. The flame never lessens its own light. It burns on as a divine light. But all these are faults that have come into the chimney set over it! The smoke called Ahaṅkāra, the dust called possessiveness. Because the dust called possessiveness settles on the outside of the chimney and the smoke called Ahaṅkāra on its inside, this dims the light of that flame. On the day man cleans away the smoke called Ahaṅkāra and the dust called possessiveness, that day the divine light, the divine principle of the Buddhi, shows itself and shines. These two alone are the root cause of man's failure to experience the light of this radiant Buddhi. Ahaṅkāra is going beyond all bounds. Attachment too is going beyond all bounds. Both of these are bound up with self-interest. Through this self-interest, sunk in Ahaṅkāra and possessiveness, man cannot see the light of the Ātma within himself.