In plain words
We must develop good resolves within us. We must follow Satya and Dharma. We must speak the word of Satya. We must cultivate good conduct. Through these sacred practices Manas becomes pure. As long as Manas is unclean, it has a name: ‘mala’. As long as this mala stays in the body, man has no comfort and no peace. Only after passing the mala does a man get a kind of peace and rest. Many of you know this. When the mala has hardened in many people and is tormenting them, doctors give an enema, clear it out and give the man some peace and comfort. Wicked feelings, wicked resolves, wicked deeds: all these are the very form of mala, impure and unholy. If we keep such impurities within, it is of no use though we put on the cleanest of clothes outside and bathe ourselves spotless. It looks like nothing but betrayal of the Ātma. That is, it means we are betraying not just Society; we are guilty of betraying the Ātma as well! We may even call such a person very cruel. We may say he is a demon who has taken a human form. So the chief point in this niyama is to achieve, along with outer purity, inner cleanness too, through these resolves of Satya, words of Satya and conduct in Satya. That is why they said, ‘Antar bahiś ca tat sarvaṃ vyāpya nārāyaṇa sthitaḥ’. What is within and without is Nārāyaṇa Himself; so we must inquire in what kind of sacred place we are to keep such a Nārāyaṇa.
Next, we must purify our Buddhi with Jñāna. What is Buddhi? It is that which has the power of inquiry. This very power of inquiry we must make still more sacred through Jñāna. Whatever work we do, we must inquire, ‘Is it right or wrong, Is it good or bad’. Am I proving myself an ideal to myself, to my family, to my society, to my country, or am I behaving merely as a wicked man who leads others into a kind of evil way? Each one must make this inquiry with his own conscience as witness.