SB 5.10.17

nāhaṁ viśaṅke sura-rāja-vajrān
 na tryakṣa-śūlān na yamasya daṇḍāt
nāgny-arka-somānila-vittapāstrāc
 chaṅke bhṛśaṁ brahma-kulāvamānāt
Word for word: 
na — not; aham — I; viśaṅke — am afraid; sura-rāja-vajrāt — from the thunderbolt of the King of heaven, Indra; na — nor; tryakṣa-śūlāt — from the piercing trident of Lord Śiva; na — nor; yamasya — of the superintendent of death, Yamarāja; daṇḍāt — from the punishment; na — nor; agni — of fire; arka — of the scorching heat of the sun; soma — of the moon; anila — of the wind; vitta-pa — of the owner of riches, Kuvera, the treasurer of the heavenly planets; astrāt — from the weapons; śaṅke — I am afraid; bhṛśam — very much; brahma-kula — the group of the brāhmaṇas; avamānāt — from offending.
Translation: 
My dear sir, I am not at all afraid of the thunderbolt of King Indra, nor am I afraid of the serpentine, piercing trident of Lord Śiva. I do not care about the punishment of Yamarāja, the superintendent of death, nor am I afraid of fire, scorching sun, moon, wind, nor the weapons of Kuvera. Yet I am afraid of offending a brāhmaṇa. I am very much afraid of this.
Purport: 

When Śrī Caitanya Mahāprabhu was instructing Rūpa Gosvāmī at the Daśāśvamedha-ghāṭa in Prayāga, He pointed out very clearly the seriousness of offending a Vaiṣṇava. He compared the vaiṣṇava-aparādha to hātī mātā, a mad elephant. When a mad elephant enters a garden, it spoils all the fruits and flowers. Similarly, if one offends a Vaiṣṇava, he spoils all his spiritual assets. Offending a brāhmaṇa is very dangerous, and this was known to Mahārāja Rahūgaṇa. He therefore frankly admitted his fault. There are many dangerous things — thunderbolts, fire, Yamarāja’s punishment, the punishment of Lord Śiva’s trident, and so forth — but none is considered as serious as offending a brāhmaṇa like Jaḍa Bharata. Therefore Mahārāja Rahūgaṇa immediately descended from his palanquin and fell flat before the lotus feet of the brāhmaṇa Jaḍa Bharata just to be excused.