2.72 This state of performing disinterested work which is preceded by the knowledge of the eternal self and which is characterised by firm wisdom, is the Brahmi-state, which secures the attainment of the Brahman (the self). After attaining such a state, he will not be deluded, i.e., he will not get again the mortal coil. Reaching this state even during the last years of life, he wins the blissful Brahman (the self) i.e., which is full of beatitude. The meaning is that he attains the self which is constituted of nothing but bliss.

Thus in the second chapter, the Lord wanted to remove the delusion of Arjuna, who did not know the real nature of the self and also did not realize that the activity named 'war' (here an ordained duty) is a means for attaining the nature of Sankhya or the self. Arjuna was under the delusion that the body is itself the self, and dominated by that delusion, had retreated from battle. He was therefore taught the knowledge called 'Sankhya' or the understanding of the self, and Yoga or what is called the path of practical work without attachment. These together have as their objective the attainment of steady wisdom (Sthitaprajnata)

This has been explained in the following verse by Sri Yamunacarya:  Sankhya and Yoga, which comprehend within their scope the understanding of the eternal self and the practical way of disinterested action respectively, were imparted in order to remove Arjuna's delusion.

Through them the state of firm wisdom can be reached.