The Hari-bhakti-vilāsa cites the following quotation from Skanda Purāṇa concerning the blaspheming of a Vaiṣṇava:
In this conversation between Mārkaṇḍeya and Bhagīratha, it is said: “My dear King, if one derides an exalted devotee, he loses the results of his pious activities, his opulence, his reputation and his sons. Vaiṣṇavas are all great souls. Whoever blasphemes them falls down to the hell known as Mahāraurava. He is also accompanied by his forefathers. Whoever kills or blasphemes a Vaiṣṇava and whoever is envious of a Vaiṣṇava or angry with him, or whoever does not offer him obeisances or feel joy upon seeing a Vaiṣṇava, certainly falls into a hellish condition.”
The Hari-bhakti-vilāsa (10.314) also gives the following quotation from Dvārakā-māhātmya:
In a conversation between Prahlāda Mahārāja and Bali Mahārāja, it is said, “Those sinful people who blaspheme Vaiṣṇavas, who are all great souls, are subjected very severely to the punishment offered by Yamarāja.”
In the Bhakti-sandarbha (313) there is a statement concerning the blaspheming of Lord Viṣṇu.
“One who criticizes Lord Viṣṇu and His devotees loses all the benefits accrued in a hundred pious births. Such a person rots in the Kumbhīpāka hell and is bitten by worms as long as the sun and moon exist. One should therefore not even see the face of a person who blasphemes Lord Viṣṇu and His devotees. Never try to associate with such persons.”
In his Bhakti-sandarbha (265), Jīva Gosvāmī further quotes from Śrīmad-Bhāgavatam (10.74.40):
“If one does not immediately leave upon hearing the Lord or the Lord’s devotee blasphemed, he falls down from devotional service.”
Similarly, Lord Śiva’s wife Satī states in Śrīmad-Bhāgavatam (4.4.17):
“If one hears an irresponsible person blaspheme the master and controller of religion, he should block his ears and go away if unable to punish him. But if one is able to kill, then one should by force cut out the blasphemer’s tongue and kill the offender, and after that he should give up his own life.”
Ref>>Srila Prabhupada Vani.
Jagannath Puri Hare Krishna Movement 