Rigveda 9.66.28

प्र सु॑वा॒न इन्दु॑रक्षाः प॒वित्र॒मत्य॒व्यय॑म् ।पु॒ना॒न इन्दु॒रिन्द्र॒मा॥

pra suvāna indurakṣāḥ pavitramatyavyayam |punāna indurindramā ||

Our plain-language meaning of this verse is waiting for scholar review.