Brahman is revealed in a prepared mind

It was said in the last mantra that ātmā is attribute-less. How can the attribute-less self be known by me?

na sandṛśe tiṣṭhati rūpamasya na cakṣuṣā paśyati kaścanainam |

hṛdā manīṣā manasābhiklṛpto ya etad viduramṛtāste bhavanti ||2-3-9||

The nature of this (ātmā) does not fall within the range of perception. No one sees this with the eye. It is revealed by the insight (gained) through the intellect, which resides in the heart. Those who know this become immortal.

In the first line, yamarāja says that the nature of ātmā (limitless brahman) doesn’t fall within the range of perception - na sandṛśe tiṣṭhati rūpamasya. Therefore, nobody can perceive it through any organs - na cakṣuṣā paśyati kaścanainam. As per experience, those which can’t be perceived do not exist, thus this sentence can be interpreted that self does not exist. But if with the mind which has refined by the teaching of śāstra, one understands this sentence, it conveys that whatever falls within the range of perception is not the self. What I claim to be myself should always be the subject, never the object of perception. The self is self evident without involving any pramana (means of knowing). I know that I am exist without any pramana.

But what is the role of śāstra as ātmajñānam? It doesn’t reveal the self evident ātmā as an object of knowing, but it reveals the true nature of ātmā which is wrongly understood. I don’t need anybody to tell me that I am exist; I only need someone to correct the wrong thinking about myself. And this nature of ātmā is communicated through the intellect, which resides in the heart - hṛdā manīṣā manasābhiklṛpto. hṛdā manīṣā means the mind which is free from wavering of doubt, emotion, likes and dislikes, etc. Only with a prepared and purified mind, the teaching will be absorbed through mere śravaṇam. When the mind is prepared, śravaṇam penetrates it easily. ya etad viduramṛtāste bhavanti - those who know this truth become immortal (released from the notion of mortality).