Brahma Sutras
ॐ संज्ञामूर्तिक्लृप्तिस्तु त्रिवृत्कुर्वत उपदेशात् ॐ ॥ २-४-२०॥
The arrangement of designation and shape, however, is by Him who made the elements tripartite, for it is taught (in the Upanishad).
english translation
OM saMjJAmUrtiklRptistu trivRtkurvata upadezAt OM ॥ 2-4-20॥
hk transliteration by Sanscript