Lecture on Srimad Bhagavatam, Canto 9, Chapter 13, Text 6 titled “Don’t criticize those in difficulty” by Prahladananda Swami.
After saying this, Maharaja Nimi, who was expert in the science of spiritual knowledge, gave up his body. Vasishtha, the great-grandfather, gave up his body also, but through the semen discharged by Mitra and Varuna when they saw Urvasi, he was born again.
Mitra and Varuna chanced to meet Urvasi, the most beautiful prostitute of the heavenly kingdom, and they became lusty. Because they were great saints, they tried to control their lust, but they could not do so, and thus they discharged semen. This semen was kept carefully in a waterpot, and Vasishtha was born from it.