Srimad Bhagvata Mahapurana: Book 6: Chapter 7: Verses 1-17
The king (Pariksit) said : For what reason were the gods forsaken by their own preceptor (the sage Brhaspati)? (Kindly tell me, O glorious sage, the transgression made by the disciples with respect to their preceptor, which brought matters to such a pass.Sri Suka replied : indra, who had transgressed the path frequented by the virtuous through arrogance caused by the lordship of the worlds, O king (Pariksit), was (one day) seated on the throne in his court, surrounded by the Maruts (the forty-nine wind-gods), the (eight) Vasus, the (eleven) Rudras, the (other) Adityas (sons of Aditi), (the classes of gods known as) the Rbhus, the Viswedevas and the Sadhyas, as well as by the (twin-born) Aswinikumaras (the celestial physicians). The (great) Maghava (another name of indra) was being waited upon and extolled. O Pariksit (a descendant of Bharata), by the Siddhas, Caranas, Gandharvas, sages who were (great) expositors of the Vedas, as well as by the Vidyadharas (celestial artistes) and Apsaras (celestial nymphs), Kinnaras (another class of celestial musicians), birds and Nagas (serpent-demons) and his praises were being sweetly sung. (Duly) provided with a white (royal) umbrella, charming as the orb of the moon, and other insignia of supreme royalty such as chowries and fans, he shone most splendid with (his spouse) Sad (the daughter of Puloma), who shared the throne with him. When, as would appear from the following account, he did not welcome-by rising (from his throne), offering a seat and other (appropriate) honours-the chief preceptor of (all) the gods including himself, Brhaspati, the foremost of sages, adored (alike) by the gods as well as the demons, as he came in, nay, (when) Indra did not stir from his seat even on seeing the sage (actually) present in the court, the enlightened sage, a (worthy) son of Angira, went out of the court at once and quietly returned to his own residence, though powerful (enough to correct his disciple ), (fully) aware of the aberration brought about by pride of affluence and power.
Realizing that very moment the disrespect shown by him towards his preceptor, Indra spontaneously himself reproached his own self in the court (in the following words):- "Oh, my conduct has been deplorably unrighteous in that the preceptor was slighted in (open) court by me, a creature of poor wits indeed and maddened by power and opulence. What prudent person will covet the fortune even of the lord of paradise, by which I, the ruler of the gods (who are predominantly Sattvika by nature), have been dragged into (the slough of) egotism (a demoniac propensity)! They do not know the highest (standard of) morality who declare that one occupying the throne of a suzerain lord should not rise (from one's seat) to receive anybody. They that believe the words of the aforesaid misleading guides-who undoubtedly (themselves) fall down into the dark regions of hell-surely sink (into the abysmal depths of hell) like those embarking on a ship of rock. Guilelessly touching his feet with my head (therefore), I shall presently propitiate the (kind-hearted) Brahmana, the preceptor of (all) the gods, who is endowed with fathomless intelligence. While Indra was pondering thus (even at the court), the all-wise Brhaspati (who knew what was going on in lndra's mind as well as what was in store for him) disappeared from his house by dint of his extraordinary Yogic power. Getting no clue to the whereabouts of his preceptor, though looking for him all round, the glorious Indra reflected by force of reason (how to get the better of his powerful enemies, the demon hosts, in the absence of a wise counsellor), but felt no peace of mind, though united with (closely and devotedly followed by) the gods.