204
Śrīmad-Bhāgavatam
[Canto 9, Ch. 14]
TRANSLATION
King Purūravā then left Agnisthālī in the forest and returned home, where he meditated all night upon Urvaśī. In the course of his meditation, the Tretā millennium began, and therefore the principles of the three Vedas, including the process of performing yajña to fulfill fruitive activities, appeared within his heart.
PURPORT
It is said,  tretāyām yajato makhaiḥ : in Tretā-yuga, if one performed  yajñas , he would get the results of those  yajñas . By performing  viṣṇu-yajña  specifically, one could even achieve the lotus feet of the Supreme Personality of Godhead. Of course,  yajña  is intended to please the Supreme Personality of Godhead. While Purūravā was meditating upon Urvaśī, the Tretā-yuga began, and therefore the Vedic  yajñas  were revealed in his heart. But Purūravā was a materialistic man, especially interested in enjoying the senses.  Yajñas  for enjoyment of the senses are called  karma-kāṇḍīya-yajñas . Therefore, he decided to perform  karma-kāṇḍīya-yajñas  to fulfill his lusty desires. In other words,  karma-kāṇḍīya-yajñas  are meant for sensuous persons, whereas  yajña  should actually be performed to please the Supreme Personality of Godhead. To please the Supreme Personality of Godhead in Kali-yuga, the  saṅkirtana-yajña  is recommended.  Yajñaiḥ saṅkirtana-prāyair yajanti hi sumedhasaḥ . Only those who are very intelligent take to  saṅkirtana-yajña  to fulfill all their desires, material and spiritual, whereas those who are lusty for sense enjoyment perform  karma-kāṇḍīya-yajñas .
TEXTS 44-45
शालीशानं गतोऽश्वत्थं शमीगर्भविलक्ष्य सः ।
तेन द्वे अरणी कृत्वा उर्वशीलोककाम्यया ॥४४॥
उर्वशीं मन्त्रतो ध्यायन्त्रधरारणिमुत्तरम् ।
अत्मानमुभयोर्मध्ये यत् तत् प्रजननं प्रभुः ॥४५॥
sthālī-sthānam gato 'śvattham śamī-garbham vilakṣya saḥ