ChU 7.4.1
संकल्पो वाव मनसो भूयान् । यदा वै संकल्पयते ऽथ मनस्यति । अथ वाचम् ईरयति । ताम् उ नाम्नीयूअति । नाम्नि मन्त्रा एकं भवन्ति । मन्त्रेषु कर्माणि
saṃkalpo vāva manaso bhūyān | yadā vai saṃkalpayate 'tha manasyati | atha vācam īrayati | tām u nāmnīyūati | nāmni mantrā ekaṃ bhavanti | mantreṣu karmāṇi
Devanagari rendered by HREEM from the edition's roman (IAST) text; the IAST is the edition's own.
'Will (saṅkalpa) is better than mind. For when a man wills, then he thinks in his mind, then he sends forth speech, and he sends it forth in a name. In a name the sacred hymns are contained, in the sacred hymns all sacrifices.
Translated by F. Max Müller