5.20 Whatever is experienced as pleasant by one staying in a body and remaining in a particular condition because of the subtle impressions of his old Karmas, and whatever is experienced as unpleasant - on attaining those two types of experiences, one should not feel joy or grief. How?  By having the mind on that 'Which is steadfast' i.e., the self, 'Undeluded,' i.e., one must be free from the delusion of identity of the steadfast self with the transient body. And how can this be?  He who knows Brahman and abides in Brahman, i.e., by becoming a knower of Brahman by instruction by the teachers - such a person abides steadily, engaged in the practices towards winning Brahman.

What is said is this:  From the instructions received from the sages who know the truth, one should learn what has to be learnt about the self. Endeavouring to actualise the same, one does not consider the body as the sefl and remains fixed in the joyous experience of the vision of the steadfast self. Let him not rejoice and grieve when he experiences pleasant and unpleasant things, as such experiences result from the Prakrti and are transient.