tad abhipretya bhagavan
sata-kratur na mamrse
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
When the most powerful Indra, the King of heaven, saw this, he considered the fact that King Prthu was going to exceed him in fruitive activities. Thus Indra could not tolerate the great sacrificial ceremonies performed by King Prthu.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
In the material world everyone who comes to enjoy himself or lord it over material nature is envious of others. This envy is also found in the personality of the King of heaven, Indra. As evident from revealed scriptures, Indra was several times envious of many persons. He was especially envious of great fruitive activities and the execution of yoga practices, or siddhis. Indeed, he could not tolerate them, and he desired to break them up. He was envious due to fear that those who performed great sacrifices for the execution of mystic yoga might occupy his seat. Since no one in this material world can tolerate another’s advancement, everyone in the material world is called matsara, envious. In the beginning of Srimad-Bhagavatam it is therefore said that Srimad-Bhagavatam is meant for those who are completely nirmatsara (nonenvious). In other words, one who is not free from the contamination of envy cannot advance in Krsna consciousness. In Krsna consciousness, however, if someone excels another person, the devotee who is excelled thinks how fortunate the other person is to be advancing in devotional service. Such nonenvy is typical of Vaikuntha. However, when one is envious of his competitor, that is material. The demigods posted in the material world are not exempt from envy.