Ramayana
यथा हि चोर: स तथा हि बुद्धस्तथागतं नास्तिकमत्र विद्धि । तस्माद्धि य: शङ्क्यतमः प्रजानाम् न नास्तिकेनाभिमुखो बुध: स्यात् ॥ २-१०९-३४
It is an exact state of the case that a mere intellection deserves to be punished as it were a thief and know an atheist to be on par with a mere intellectual. Therefore he is the most suspectable and should be punished in the interest of the poeple. In no case should a wise man consort with an atheist. ॥ 2-109-34॥
english translation
yathA hi cora: sa tathA hi buddhastathAgataM nAstikamatra viddhi । tasmAddhi ya: zaGkyatamaH prajAnAm na nAstikenAbhimukho budha: syAt ॥ 2-109-34
hk transliteration by Sanscript