Bhashya
तयोः वर्तन्योः अन्यतरां वर्तनीं मनसा विवेकज्ञानवता संस्करोति ब्रह्मा ऋत्विक्, वाचा वर्तन्या होताध्वर्युरुद्गाता इत्येते त्रयोऽपि ऋत्विजः अन्यतरां वागलक्षणां वर्तनीं वाचैव संस्कुर्वन्ति ।तत्रैवं सति वाङ्मनसे वर्तनी संस्कार्ये यज्ञे ।अथ स ब्रह्मा यत्र यस्मिन्काले उपाकृते प्रारब्धे प्रातरनुवाके शस्त्रे, पुरा पूर्वं परिधानीयाया ऋचः ब्रह्मा एतस्मिन्नन्तरे काले व्यवदति मौनं परित्यजति यदि, तदा अन्यतरामेव वाग्वर्तनीं संस्करोति ।ब्रह्मणा संस्क्रियमाणा मनोवर्तनी हीयते विनश्यति छिद्रीभवति अन्यतरा; स यज्ञः वाग्वर्तन्यैव अन्यतरया वर्तितुमशक्नुवन रिष्यति ।
In plain words
Of the two paths of the sacrifice, the Brahma priest purifies the path of the mind through discernment, while the three priests—the Hotṛ, Adhvaryu, and Udgātṛ—purify the path of speech through spoken words. Thus speech and mind are the two paths that must be refined within the ritual. If the Brahma breaks his silence and speaks during the interval after the morning litany has begun and before the final verse, he tends only to the path of speech. Left unrefined, the mental path lapses, frays, and breaks down. Unable to move forward on the single path of speech alone, the sacrifice is ruined.
Close to the Sanskrit
Of those two paths, the Brahma priest refines one path, the mind-path, through discriminative knowledge. The Hotṛ, Adhvaryu, and Udgātṛ priests—these three priests—refine the other path, the speech-path, by speech alone. Thus, speech and mind are the two paths to be purified in the sacrifice. Now, if that Brahma speaks out and abandons his silence at that time—after the morning litany and the praise have begun, prior to the concluding verse—then he refines only the speech-path. The mind-path, being left unrefined by the Brahma, is abandoned, perishes, and becomes flawed. That sacrifice, unable to proceed by means of only one path—the speech-path—comes to ruin.