Valmiki Ramayana 6.89.2

तस्य ज्यातलनिर्घोषं स श्रुत्वा रावणात्मजः।विवर्णवदनो भूत्वा लक्ष्मणं समुदैक्षत॥

tasya jyātalanirghoṣaṃ sa śrutvā rāvaṇātmajaḥ |vivarṇavadano bhūtvā lakṣmaṇaṃ samudaikṣata ||

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