hanti nindati vai dveṣṭi
hanti nindati vai dveṣṭi vaiṣṇavān nābhinandati |
krudhyate yāti no harṣaṁ darśane patanāni ṣaṭ ||
(Skanda Purāṇa; cited in Hari-bhakti-vilāsa 10.312, Bhakti Sandarbha: 265)
“Striking, defaming, despising, not respectfully greeting, getting angry with, and not being joyful upon seeing Vaiṣṇavas are six causes of falling [into Naraka].”