“What is” exists;  “What is not” doesn’t

16: For what does not exist, there is no existence. For what is, there is no non-existence. The people who knew the truth, know the reality of these statements clearly.

For the qualities such as heat and cold, joy and sorrow which are Asat – not known or unmanifest and for the cause of the manifestation of heat and cold, there is no real existence. There is indeed no real object which is the cause for heat and cold. Heat and cold, joy and sorrow are experienced in the mind. There is no real object called the mind. Heat and cold are mere modifications. That which shifts shape keeps changing. Just as forms like pot etc. are seen by the eyes is not different from mud, Asat is not experienced as it is the modification of all names and forms.

What is not comprehended before birth and after death is Asat. Further soil is the cause for mud. It is not appearing different from its cause. So it is Asat because soil alone exists. In this manner, the construction of Buddhi is divided as Sat and Asat. Everywhere and with everybody there are two types of steady thoughts that indicate one object.

Everywhere it is common to say pot is, canvas is, elephant is. It is not common like blue lotus.

That which exists is changeless: 

Among the two types of thought, the concept of pot can change, not its existence. In the same way it is shown pot etc. are Asat because it changes. The existence thought is not Asat because it does not change. If the pot is destroyed, the pot thought also changes. In the sasme way if it can be said that the mud thought also changes? No because there is existence thought in canvas and other objects. The existence thought refers to the content of what is. Just as Sadbuddhi does not change even after the pot breaks can we call it as existence? No, because the canvas is not seen there. If Sad Buddhi also disappears with the disappearance of the pot? No, there is no specific object such as pot. Sadbuddhi is vishesham or the content. Its visheshya is the form. When the form is not there, what is pointed out? Not indeed. in Sat or existence thought there are no objects. If the objects such as pot are absent, how can it be said, Pot is? No. In the case of a mirage, even when there is no water, since there is understanding of water, the object is the same.

There are no dualities:

Therefore, regarding the body, mind and intellect. the dualities of heat and cold and their cause have no existence. The Atman which is Sat does not have non-existence or the experience of being not known. It does not change anywhere as we have said.

In this manner, Sat is Atma and Asat is Anatma. The conclusion of the two has been made by the Seers of the truth. How is that? Sat is Sat and Asat is Asat. They have known this for real. Tat is a common noun. All is Brahman. That is the expression. The essence is the reality of Brahman. Those who are capable of seeing this are Tatwa Darshi.

You too O Arjuna, taking a cue from Tatwa Darshis destroy sorrow and delusion. Bear with the dual modifications of heat-cold etc. which gives the clear conclusion that this is Asat. like a mirage water having a false appearance. Being firm on this conclusion in your mind, put up with difficulties. This is the idea.