SB 4.25.7
narada uvaca
bhoh bhoh prajapate rajan
pasun pasya tvayadhvare
samjñapitañ jiva-sanghan
nirghrnena sahasrasah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The great saint Narada said: O ruler of the citizens, my dear King, please see in the sky those animals which you have sacrificed without compassion and without mercy in the sacrificial arena.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Because animal sacrifice is recommended in the Vedas, there are animal sacrifices in almost all religious rituals. However, one should not be satisfied simply by killing animals according to the directions of the scriptures. One should transcend the ritualistic ceremonies and try to understand the actual truth, the purpose of life. Narada Muni wanted to instruct the King about the real purpose of life and invoke a spirit of renunciation in his heart. Knowledge and the spirit of renunciation (jñana-vairagya) are the ultimate goal of life. Without knowledge, one cannot become detached from material enjoyment, and without being detached from material enjoyment, one cannot make spiritual advancement. Karmis are generally engaged in sense gratification, and for this end they are prepared to commit so many sinful activities. Animal sacrifice is but one such sinful activity. Consequently, by his mystic power Narada Muni showed King Pracinabarhisat the dead animals which he had sacrificed.