Shiva Purana
सत्यमाहुः परं धर्मं सत्यमाहुः परं पदम् ॥ सत्यमाहुः परं ब्रह्म तस्मात्सत्यं सदा वदेत् ॥ ३१ ॥
They say that Truth is the greatest virtue, the greatest region, the greatest Brahman; hence one shall tell the Truth always.
english translation
satyamAhuH paraM dharmaM satyamAhuH paraM padam ॥ satyamAhuH paraM brahma tasmAtsatyaM sadA vadet ॥ 31 ॥
hk transliteration by Sanscript