Brahma Sutras
ॐ वदतीति चेन्न प्राज्ञो हि ॐ ॥ १-४-५॥
If it be argued that the Upanishad does mention Pradhana (by the word avyakta), we say: No, for the conscious Self is understood from the context.
english translation
OM vadatIti cenna prAjJo hi OM ॥ 1-4-5॥
hk transliteration by Sanscript