In plain words
He himself becomes Brahman. It is just by following the senses that we turn into beasts. Follow at least Manas, and stand as a man. Even if you do not become a noble soul by following Buddhi, live at least as a man by following Manas. But many may have a doubt here: surely Manas too is quite bad? Manas is always pure. On this side, by following the senses, it takes on impurity. Manas gathers the stuff of the sense objects that the senses have gathered. Manas takes in no object at all. Manas is the master of the senses. Because the senses, followers of this Manas, gather many objects and give them to Manas, Manas sits comfortably and dines. But if this Manas follows Buddhi even a little, that Buddhi comes and tells Manas: this is fit to be done, this is not fit to be done. This must not be accepted, this may be accepted: so it decides. But Manas does not consult Buddhi at all. Because this Manas enjoys only what the senses give it, it takes on impurity.
Through all these past days we have learnt about the four: body, senses, Manas and Buddhi. The single form of these four was called the kṣetra. This kṣetra is wholly inert. Manas is inert. The senses are inert. The body is inert. So today we have learnt about what is inert. How is the nature of these inert things controlled? That is the kṣetrajña. Between this kṣetra and kṣetrajña there is some room. The unfolding of creation. This kṣetra keeps friendship with certain other things too, with what is impure and with what is pure. These are the three guṇas. The sattva, rajas and tamas guṇas. These three guṇas, sattva, rajas and tamas, are very strange. They are full of wonder. How were these created, and in what way are the three guṇas the basis of this creation? Tomorrow we shall learn why this world is called a world whose form is the three guṇas. I think that even now you will truly not have heard of the creation of the three guṇas. You must try to grasp such a subject well tomorrow.