CHĀNDOGYA UPANISHAD · 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 ॥

'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.

F. Max Müller · The Upanishads, Sacred Books of the East 1 (1879)