Shiva Purana
यथा दीपस्य दीप्तस्य शिखा दीपयते गृहम् ॥ तथा तेजस्तयोरेतद्व्याप्य दीपयते जगत् ॥ ६९ ॥
As the flame of the brilliant lamp illuminates the house so also their brilliance pervades the universe and illuminates it.
english translation
yathA dIpasya dIptasya zikhA dIpayate gRham ॥ tathA tejastayoretadvyApya dIpayate jagat ॥ 69 ॥
hk transliteration by Sanscript