Bhashya
स्थानप्रयत्नादस्वरवर्णपदवाक्यविषया तत्सकल्पात्मिका त-द्भाविता वृत्ति श्रोत्रकरणद्वारा यजु संकेतेन विशिष्टा यजु-रित्युच्यते ।एवम ऋक्, एव साम च ।एव चमनोवृत्तित्वे मन्त्राणाम्, वृत्तिरेव आवर्त्यत इति मानसोजप उपपद्यते ।अन्यथा अविषयत्वान्मन्त्रो नावर्तयितुशक्य घटादिवत् इति मानसो जपो नोपपद्यते ।मन्त्रावृत्तिश्चोच्यते बहुश कर्मसु ।अक्षरविषयस्मृत्यावृत्त्या मन्त्रा-वृत्ति स्यात् इति चेत्, न, मुख्यार्थासंभवात् ।'त्रिप्रथमाम वाह त्रिरुत्तमाम्' इति ऋगावृत्ति श्रूयते ।तत्रऋच अविषयत्वे तद्विषयस्मृत्यावृत्त्या मन्त्रावृत्तौ च क्रिय-माणायाम् 'त्रि प्रथमा मन्वाह' इति ऋगावृत्तिर्मुख्योऽर्थ-श्चोदित परित्यक्त स्यात् ।तस्मान्मनोवृत्त्युपाधिपरिच्छिन्नमनोवृत्तिनिष्ठमात्मचैतन्यमनादिनिधन यजु शब्दवाच्यम् आत्मविज्ञान मन्त्रा इति ।एव च नित्यत्वोपपत्तिर्वेदानाम् ।अन्यथाविषयत्वे रूपादिवदनित्यत्व च स्यात्, नैतद्युक्तम् ।'सर्वेवेदा यत्रैक भवन्ति स मानसीन आत्मा' इति च श्रुतिनित्यात्मनैकत्व ब्रुवन्ती ऋगादीना नित्यत्वे समञ्जसा स्यात् ।'ऋचोऽक्षरे परमे व्योमन्यस्मिन्देवा अधि विश्वे निषेदु 'इति च मन्त्रवर्ण ।आदेश अत्र ब्राह्मणम्, आदेश्यव्यवि-शेषानादिशतीति ।अथर्वणाङ्गिरसा च दृष्टा मन्त्रा ब्राह्मणं च शान्तिकपौष्टिकादिप्रतिष्ठाहेतुकर्मप्रधानत्वात् पुच्छं प्रतिष्ठा ।तदप्येष श्लोको भवति मनोमयात्मप्रकाशक पूर्ववत् ॥
In plain words
A mantra is not a mere physical sound; it is a wave of consciousness within the mind. When the mind, through intention and focus, shapes itself into the patterns of vowels, letters, and words, that very thought-wave is the mantra. This is why silent, mental repetition is possible—for we are repeating a state of consciousness, not a physical object. If mantras were just external sounds, they could no more be repeated internally than a physical clay pot. This understanding preserves the eternal nature of the Vedas: they are not temporary physical sounds, but the beginningless, endless light of pure Consciousness reflecting through the medium of the mind. As the ancient sages saw, the sacred verses dwell in the supreme, imperishable space of consciousness. To reveal this mental self, the following verse is given.
Close to the Sanskrit
A mental modification concerned with vocal organs, internal effort, vowels, phonemes, words, and sentences, characterized by mental resolve, saturated by those sounds, and qualified by the designation of Yajur through the organ of hearing, is called 'Yajur'. In the same manner is Rig, and in the same manner is Sama. And since mantras are thus modifications of the mind, the mental wave itself is repeated, and therefore silent repetition becomes logically possible. Otherwise, if they were not objects of the mind, a mantra could not be repeated, just like a physical pot, and silent repetition would not be possible. Mantras and their repetition are frequently mentioned in ritual contexts. If it is argued that the repetition of a mantra is achieved by repeating the memory of its syllables, we say no, because that would make the primary meaning of the scriptural injunction impossible. The repetition of Rig verses is prescribed in scripture. In that context, if the Rig verse itself were not the direct object of repetition, and instead one merely repeated the memory of it, the direct literal meaning of the injunction 'he recites the first verse thrice' would have to be discarded. Therefore, the eternal, beginningless, and endless consciousness of the Self, conditioned by the limiting adjunct of the mind's modifications and abiding in them, is signified by the word 'Yajur'—such is the knowledge of the Self that constitutes the mantras. And in this way, the eternal nature of the Vedas is logically established. Otherwise, if they were objects of sensory perception, they would be impermanent like physical forms, which is not correct. The scripture declaring unity with the eternal Self, saying 'where all Vedas become one, that is the Self within the mind,' is perfectly coherent only if the Rig and other Vedas are eternal. And there is also the text of the mantra: 'The Rig verses reside in the supreme, imperishable space where all the gods dwell.' The word 'ādeśa' here refers to the Brāhmaṇa portion, because it instructs or enjoins specific duties. The mantras and Brāhmaṇas revealed to Atharvan and Angiras constitute the tail, the support, because they are prominent in rituals that cause stability, such as rites for peace and prosperity. On that point also, there is this verse revealing the mental self, just as before.