RV 1.164.39
ऋचो अक्षरे परमे व्योमन् यस्मिन् देवा अधि विश्वे निषेदुः । यस् तन् न वेद किम् ऋचा करिष्यति य इत् तद् विदुस् त इमे सम् आसते ॥
ṛco akṣare parame vyoman yasmin devā adhi viśve niṣeduḥ | yas tan na veda kim ṛcā kariṣyati ya it tad vidus ta ime sam āsate ||
Devanagari rendered by HREEM from the edition's roman (IAST) text; the IAST is the edition's own.
Upon what syllable of holy praise-song, as twere their highest heaven, the Gods repose them,-- Who knows not this, what will he do with praise-song? But they who know it well sit here assembled.
Translated by Ralph T. H. Griffith (1896)