Shiva Purana
विकल्परहितं तत्त्वं परमित्यभिधीयते ॥ वैपरीत्यादसच्छब्दः कथ्यते वेदवादिभिः ॥ ९ ॥
The great principle is devoid of alteration or doubts. The opposite thing is connoted by the word Asat as explained by those who propound the Vedas.
english translation
vikalparahitaM tattvaM paramityabhidhIyate ॥ vaiparItyAdasacchabdaH kathyate vedavAdibhiH ॥ 9 ॥
hk transliteration by Sanscript