Srimad-Bhagavatam: Canto 5 - Chapter 1 - Verse 30

Sanskrit:

अथ च यस्त्विह वा आत्मसम्भावनेन स्वयमधमो जन्मतपोविद्याचारवर्णाश्रमवतो वरीयसो न बहु मन्येत स मृतक एव मृत्वा क्षारकर्दमे निरयेऽवाक्‌शिरा निपातितो दुरन्ता यातना ह्यश्नुते ॥ ३० ॥

ITRANS:

atha ca yas tv iha vā ātma-sambhāvanena svayam adhamo janma-tapo-vidyācāra-varṇāśramavato varīyaso na bahu manyeta sa mṛtaka eva mṛtvā kṣārakardame niraye ’vāk-śirā nipātito durantā yātanā hy aśnute.

Translation:

A lowborn and abominable person who in this life becomes falsely proud, thinking “I am great,” and who thus fails to show proper respect to one more elevated than he by birth, austerity, education, behavior, caste or spiritual order, is like a dead man even in this lifetime, and after death he is thrown headfirst into the hell known as Kṣārakardama. There he must suffer great tribulation at the hands of the agents of Yamarāja.

Purport:

One should not become falsely proud. One must be respectful toward a person more elevated than he by birth, education, behavior, caste or spiritual order. If one does not show respect to such highly elevated persons but indulges in false pride, he receives punishment in Kṣārakardama.