Srimad-Bhagavatam: Canto 7 - Chapter 1 - Verse 16

Sanskrit:

श्रीयुधिष्ठिर उवाचअहो अत्यद्भ‍ुतं ह्येतद्दुर्लभैकान्तिनामपि ।वासुदेवे परे तत्त्वे प्राप्तिश्चैद्यस्य विद्विष: ॥ १६ ॥

ITRANS:

śrī-yudhiṣṭhira uvācaaho aty-adbhutaṁ hy etaddurlabhaikāntinām apivāsudeve pare tattveprāptiś caidyasya vidviṣaḥ

Translation:

Mahārāja Yudhiṣṭhira inquired: It is very wonderful that the demon Śiśupāla merged into the body of the Supreme Personality of Godhead even though extremely envious. This sāyujya-mukti is impossible to attain even for great transcendentalists. How then did the enemy of the Lord attain it?

Purport:

There are two classes of transcendentalists — the jñānīs and the bhaktas. The bhaktas do not aspire to merge into the existence of the Lord, but the jñānīs do. Śiśupāla, however, was neither a jñānī nor a bhakta, yet simply by envy of the Lord he attained an exalted position by merging into the Lord’s body. Certainly this was astonishing, and therefore Mahārāja Yudhiṣṭhira inquired about the cause for the Lord’s mysterious mercy to Śiśupāla.