Verse 5.5

यः पुनरेतं त्रिमात्रेणोमित्येतेनैवाक्शरेण परं पुरुषमभिध्यायीत स तेजसि सूर्ये संपन्नः । यथा पादोदरस्त्वचा विनिर्भुच्यत एवं ह वै स पाप्मना विनिर्भुक्तः स सामभिरुन्नीयते ब्रह्मलोकं स एतस्माज्जीवघनात्परात्परं पुरुशयं पुरुषमीक्शते तदेतौ श्लोकौ भवतः ॥ ५ ॥

yaḥ punaretaṃ trimātreṇomityetenaivākśareṇa paraṃ puruṣamabhidhyāyīta sa tejasi sūrye saṃpannaḥ | yathā pādodarastvacā vinirbhucyata evaṃ ha vai sa pāpmanā vinirbhuktaḥ sa sāmabhirunnīyate brahmalokaṃ sa etasmājjīvaghanātparātparaṃ puruśayaṃ puruṣamīkśate tadetau ślokau bhavataḥ || 5 ||

5. But if he meditates on the supreme Purusha by this very letter ‘Om,’ of three matras, he becomes united with the bright sun. Just as the snake puts off its skin, even so he is freed from sin. He is conducted by sama to the world of Brahma. He sees the supreme Purusha beyond this, dense with life and lodged in the heart of all. There are the two following verses.

Shankara’s Commentary:

Com.—But he who meditates upon the supreme Purusha within the sun, by this pratika, i.e., substitute, i.e., by the syllable ‘Om’ with the knowledge that it is of three matras, by such meditation becomes united with the sun. According to the context, the syllable ‘Om’ must be taken to be a help, being a Pratika or substitute, from the declaration of its identity with the Brahman, higher and lower, according to the sruti. Otherwise, the accusative case of ‘Om’ used in many places, will be objectionable. Though by the use of the third case, the syllable ‘Om’ may be understood as a karana, i.e., instrument, still agreeably to the context, it must be read as if in the accusative case, the meaning then being, ‘let one meditate upon the syllable of three matras as the supreme Purusha.’ According to the maxim ‘you may abandon one for the benefit of a whole family’ the instrumental case should be here given up for the accusative case used in previous passages. By such meditation, he becomes united with the bright sun. Then, even if he dies while meditating, he does not return from the solar world as from the lunar, but is for ever united with the sun. Just as the snake puts off its skin and becomes new again, its skin having been peeled off, so—as in this illustration—this man being freed from the impurity of sin, analogous to the skin, is conducted up, by the samans representing the third matra, to the world of Brahma, i.e., Hiranyagarbha called Satya. He, Hiranyagarbha is the atman of all the jivas travelling in samsara; for, he is the internal atman of all living beings in the subtle form; and in him the subtle atman are all the jivas strung together. So he is jivaghana (dense with lives). The knower of the syllable ‘Om’ of the three matras sees the Purusha called Paramatman beyond this Hiranyagarbha and sees him by meditation as lodged in all bodies. The following two verses make the drift stated clear.