Rigveda 10.181.2

अवि॑न्द॒न्ते अति॑हितं॒ यदासी॑द्य॒ज्ञस्य॒ धाम॑ पर॒मं गुहा॒ यत् ।धा॒तुर्द्युता॑नात्सवि॒तुश्च॒ विष्णो॑र्भ॒रद्वा॑जो बृ॒हदा च॑क्रे अ॒ग्नेः॥

avindante atihitaṃ yadāsīdyajñasya dhāma paramaṃ guhā yat |dhāturdyutānātsavituśca viṣṇorbharadvājo bṛhadā cakre agneḥ ||

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