In plain words
But most people are making their life impure on the path of pravṛtti itself. They make no enquiry at all about nivṛtti. So we must guard nivṛtti, too, with care, to some extent. If the charioteer has no reins in his hands, the horses themselves will not go. Because the charioteer has let go of the reins, these horses are running off. And these horses are no ordinary horses. They go on, looking only for the enjoyment of sense objects. Each horse turns in a different direction. So who is in this danger? Not the chariot alone: this danger comes to those in the chariot as well. So today they are making the body impure. We are rooting out the principle of the Ātma that is in the body. Today we are turning out like the washerman who lost on both sides. So if we want to recognise humanness, we must recognise well the nature of Manas. In man they are always brooding over harm to others. This is very dangerous. Fools imagine that by brooding over harm to others some good will come to them. The man who wishes harm to others: even if the harm does befall the others, that harm turns back on him many times over and keeps tormenting him. Today's man makes no effort to recognise this. The fit example of this is Duryodhana, Duśśāsana and the rest. They nursed many kinds of grudges against the Pāṇḍavas, who were Dharma in human form, and kept thinking all the time of harm to them. Granted, their saṅkalpas were bad saṅkalpas, and their effect did fall on the Pāṇḍavas; yet in the end, what came of it? Harm many times greater befell them themselves.
Students! You must recognise this matter well. We should not wish harm to anyone. If we wish others one part of harm, ten parts of harm come to us. We must not revile anyone else. When you revile others, many will revile you. He who deceives his friends is deceived by friends. He who defies his father's word is himself defied by his own son. He who torments others is tormented by others. This reaction, reflection, resound is the effect of Manas. So we should never try in any way to revile anyone or to torment anyone.