Srimad-Bhagavatam: Canto 11 - Chapter 1 - Verse 24

Sanskrit:

स्‍नानभोजनहोमेषु जपोच्चारे च वाग्यत: ।न च्छिन्द्यान्नखरोमाणि कक्षोपस्थगतान्यपि ॥ २४ ॥

ITRANS:

snāna-bhojana-homeṣujapoccāre ca vāg-yataḥna cchindyān nakha-romāṇikakṣopastha-gatāny api

Translation:

A brahmacārī should always remain silent while bathing, eating, attending sacrificial performances, chanting japa or passing stool and urine. He should not cut his nails and hair, including the armpit and pubic hair.

Purport:

Nārada Muni gives a similar technical description of Vedic brahmacārī life in Canto Seven, Chapter Twelve, of Śrīmad-Bhāgavatam.