Śānti-parva Adhyāya 30: Nārada–Parvata Samaya-bhaṅga, Śāpa, and the Marriage of Sukumārī
इत्युक्तेन मया पश्चाच्छप्तस्त्वमपि मत्सरात् | अद्यप्रभृति वै वासं स्वर्गे नावाप्स्यसीति ह
ity uktena mayā paścāc chaptas tvam api matsarāt | adyaprabhṛti vai vāsaṃ svarge nāvāpsyasīti ha ||
इत्युक्तेन मया पश्चाच्छप्तस्त्वमपि मत्सरात् । अद्यप्रभृति वै वासं स्वर्गे नावाप्स्यसीति ह ॥
श्रीकृष्ण उवाच
Jealousy (mātsarya) is ethically corrosive: it provokes harmful intent and invites karmic consequences, here expressed as the loss of svarga—symbolizing forfeiture of the fruits of merit and right conduct.
Kṛṣṇa reports that after he spoke, the addressed person—motivated by envy—became subject to a curse declaring that from that day forward he would not attain residence in heaven.