Verse 2.10.1

अथ खल्वात्मसंमितमतिमृत्यु सप्तविधं सामोपासीत हिंकार इति त्र्यक्षरं प्रस्ताव इति त्र्यक्षरं तत्समम् ॥ २.१०.१ ॥

atha khalvātmasaṃmitamatimṛtyu saptavidhaṃ sāmopāsīta hiṃkāra iti tryakṣaraṃ prastāva iti tryakṣaraṃ tatsamam || 2.10.1 ||

1. After worshipping the Sāma as the sun, one should perform the sevenfold Sāma worship by using words of the same number of syllables. By this one overcomes death. The word hiṃkāra has three syllables; so also,

Word-for-word explanation:

Atha, next [i.e., after worshipping the sun as the Sāma]; khalu, for certain; ātma-sammitam, with an equal number of parts [i.e., syllables]; atimṛtyu, that which overcomes death; saptavidham sāma upāsīta, one should perform the sevenfold Sāma worship; hiṃkāraḥ, the word hiṃkāra; iti tryakṣaram, is three-syllabled; prastāvaḥ, the word prastāva; iti tryakṣaram, is [also] three-syllabled; tat samam, therefore they [hiṃkāra and prastāva] are equal.

Commentary:

Śaṅkara says that the sun divides time into units. It therefore distinguishes between life and death, and it is death itself. Is there any way of overcoming death? Yes, it can be overcome by worshipping the Sāma, and that is why these instructions are being given here.