Srimad-Bhagavatam: Canto 6 - Chapter 1 - Verse 22

Sanskrit:

तस्यायमनयस्यासीत् परेभ्यो व: पराभव: ।प्रक्षीणेभ्य: स्ववैरिभ्य: समृद्धानां च यत्सुरा: ॥ २२ ॥

ITRANS:

tasyāyam anayasyāsītparebhyo vaḥ parābhavaḥprakṣīṇebhyaḥ sva-vairibhyaḥsamṛddhānāṁ ca yat surāḥ

Translation:

Because of your misbehavior toward Bṛhaspati, you have been defeated by the demons. My dear demigods, since the demons were weak, having been defeated by you several times, how else could you, who were so advanced in opulence, be defeated by them?

Purport:

The devas are celebrated for fighting with the asuras perpetually. In such fights the asuras were always defeated, but this time the demigods were defeated. Why? The reason, as stated here, was that they had offended their spiritual master. Their impudent disrespect of their spiritual master was the cause of their defeat by the demons. As stated in the śāstras, when one disrespects a respectable superior, one loses his longevity and the results of his pious activities, and in this way one is degraded.