Brahma Sutras
ॐ युक्तेः शब्दान्तराच्च ॐ ॥ २-१-१८॥
(The pre-existence and non-difference of the effect are established) from reasoning and another Upanishadic text.
english translation
OM yukteH zabdAntarAcca OM ॥ 2-1-18॥
hk transliteration by Sanscript