स्वस्थं शान्तं सनिर्वाणमकथ्यं सुखमुत्तमम् ।
अजमजेन ज्ञेयेन सर्वज्ञं परिचक्षते ॥ ४७ ॥svasthaṃ śāntaṃ sanirvāṇamakathyaṃ sukhamuttamam |
ajamajena jñeyena sarvajñaṃ paricakṣate || 47 ||47. This highest bliss is based upon the realisation of Self it is peace, identical with liberation, indescribable and unborn. It is further described as the omniscient Brahman, because it is one with the unborn Self which is the object sought by Knowledge.
Shankara Bhashya (commentary)
The above-mentioned bliss which is the highest1 Reality and which is characterised by the knowledge of the Ātman is2 centred in the Self. It is all peace, characterised by the cessation of all evils. It is the same as liberation.3 It is indescribable as4 nobody is able to describe it; for, it is totally different from all objects. This ultimate bliss is directly realized by the Yogis.5 It is unborn because it is not produced like anything resulting from empirical perceptions. It is identical with the Unborn which is the object sought by Knowledge. The Knowers of Brahman describe this bliss verily as the omniscient Brahman, as it is identical with that Reality which is omniscient.
Anandagiri Tika (glossary)
Now is described the nature of the mind in the state of the highest realisation.
1 Highest—It is distinguished from the happiness described in Kārikā 45, which is of the same class as relative bliss.
2 Is centred, etc.—This is to show that Self-realisation does not depend upon anything external to itself.
3 Liberation—The state of liberation, on account of its identity with Truth, is characterised by the attainment of all-absorbing happiness and cessation of all miseries.
4 As, etc.—It is because this happiness transcends all subject object relationship.
5 Yogis—These Yogis are not like the ordinary ones. The nature of their Yoga has been described as the Asparśa Yoga in Kārikā 3. 39.