Verse 2.22.3

सर्वे स्वरा इन्द्रस्यात्मानः सर्व ऊष्माणः प्रजापतेरात्मानः सर्वे स्पर्शा मृत्योरात्मानस्तं यदि स्वरेषूपालभेतेन्द्रंशरणं प्रपन्नोऽभूवं स त्वा प्रति वक्ष्यतीत्येनं ब्रूयात् ॥ २.२२.३ ॥

sarve svarā indrasyātmānaḥ sarva ūṣmāṇaḥ prajāpaterātmānaḥ sarve sparśā mṛtyorātmānastaṃ yadi svareṣūpālabhetendraṃśaraṇaṃ prapanno'bhūvaṃ sa tvā prati vakṣyatītyenaṃ brūyāt || 2.22.3 ||

3. All the vowels are like Indra’s body with its various parts. The sibilants [śa, ṣa, etc.] are like Prajāpati’s body with its various parts. The consonants, starting with ka, are the body and limbs of Death. If someone finds fault with the way the udgātā pronounces the vowels, he may say to that person: ‘As I began singing, I took refuge in Indra [i.e., I sought Indra’s blessings]. Ask him and he will give you the right answer [to your criticism].’

Word-for-word explanation:

Sarve svarāḥ, all the vowels; indrasya ātmānaḥ, are like the body [with its limbs] of Indra; sarve ūṣmāṇaḥ, all the sibilants; prajāpateḥ ātmānaḥ, are like the body [with its limbs] of Prajāpati; sarve sparśāḥ, all the consonants, starting with ka; mṛtyoḥ ātmānaḥ, are like the body [with all its limbs] of Death; yadi upālabheta, if anyone criticizes; tam, him [the udgātā, who is singing the Sāma]; svareṣu, regarding his pronunciation of the vowels; indram śaraṇam prapannaḥ abhūvam, [the udgātā will then say:] I took refuge in Indra [when I started singing the vowels]; saḥ, he [Indra]; tvā prativakṣyati iti, will give you the right reply; enam brūyāt, say to him.

Commentary:

The vowels are said to be Indra’s body, for when you start doing something, including even a recitation, you have to feel strong enough to do the job fully and correctly. And in order that you may feel that you have the requisite strength, you pray for Indra’s blessings, and you feel that he is transmitting his strength to you. You feel that the vowels you are using are his body, the sibilants are the body of Prajāpati, and the consonants are the body of Death. Then if anyone criticizes your pronunciation of the vowels, you can tell him to ask Indra for the reason