One verse

Srimad Bhagavatam 11.17.24

11.17.24

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

snāna-bhojana-homeṣu japoccāre ca vāg-yataḥ na cchindyān nakha-romāṇi kakṣopastha-gatāny api

snāna
while bathing
bhojana
while eating
homeṣu
and while attending sacrificial performances
japa
while chanting mantras to oneself
uccāre
while passing stool or urine
ca
also
vāk-yataḥ
remaining silent
na
not
chindyāt
should cut
nakha
the nails
romāṇi
or hairs
kakṣa
in the armpits
upastha
pubic
gatāni
including
api
even

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.