Srimad Bhagavatam Canto 05, Chapter 01, Text 26

SB 5.1.26

etesam kavir mahavirah savana iti traya asann urdhva-retasas ta atma-vidyayam arbha-bhavad arabhya krta-paricayah paramahamsyam evasramam abhajan.
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
Three among these ten — namely Kavi, Mahavira and Savana — lived in complete celibacy. Thus trained in brahmacari life from the beginning of childhood, they were very conversant with the highest perfection, known as the paramahamsa-asrama.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
The word urdhva-retasah in this verse is very significant. Urdhva-retah refers to one who can control sex life and who instead of wasting semen by discharging it can use this most important substance accumulated in the body to enrich the brain. One who can completely control sex life is able to work wonderfully with his brain, especially in remembering. Thus students who simply hear Vedic instructions once from their teacher could remember them verbatim without needing to read books, which therefore did not exist in former times.
Another significant word is arbha-bhavat, which means “from very childhood.” Another meaning is “from being very affectionate to children.” In other words, paramahamsa life is dedicated for the benefit of others. Just as a father sacrifices many things out of affection for his son, great saintly persons sacrifice all kinds of bodily comforts for the benefit of human society. In this connection there is a verse concerning the Six Gosvamis:
tyaktva turnam asesa-mandala-pati-srenim sada tucchavat
 bhutva dina-ganesakau karunaya kaupina-kanthasritau
Because of their compassion for the poor fallen souls, the Six Gosvamis gave up their exalted positions as ministers and took vows as mendicants. Thus minimizing their bodily wants as far as possible, they each accepted only a loincloth and a begging bowl. Thus they remained in Vrndavana to execute the orders of Sri Caitanya Mahaprabhu by compiling and publishing various Vaisnava literatures.
Srimad Bhagavatam Canto 05, Chapter 01, Text 25
Srimad Bhagavatam Canto 05, Chapter 01, Text 27