SB 4.19.15
vadhan nivrttam tam bhuyo
hantave ’trir acodayat
jahi yajña-hanam tata
mahendram vibudhadhamam
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
When Atri Muni saw that the son of King Prthu did not kill Indra but returned deceived by him, Atri Muni again instructed him to kill the heavenly King because he thought that Indra had become the lowliest of all demigods due to his impeding the execution of King Prthu’s sacrifice.