Srimad Bhagavatam Canto 11, Chapter 17, Text 23

SB 11.17.23

mekhalajina-dandaksa-
 brahma-sutra-kamandalun
jatilo ’dhauta-dad-vaso
 ’rakta-pithah kusan dadhat
 
Translation: 
 
The brahmacari should regularly dress with a belt of straw and deerskin garments. He should wear matted hair, carry a rod and waterpot and be decorated with aksa beads and a sacred thread. Carrying pure kusa grass in his hand, he should never accept a luxurious or sensuous sitting place. He should not unnecessarily polish his teeth, nor should he bleach and iron his clothes.
 
Purport: 
 
The word adhauta-dad-vasa indicates that a renounced brahmacari is not concerned with a glistening smile to attract the opposite sex, nor does he pay much attention to his outer garments. Brahmacari life is meant for austerity and obedience to the spiritual master so that later in life, when one becomes a businessman, politician or intellectual brahmana, one will be able to call upon resources of character, discipline, self-control, austerity and humility. Student life, as described here, is far different from the mindless hedonism known as modern education. Of course, in the modern age, Krsna conscious brahmacaris cannot artificially adopt the ancient dress and ritualistic duties described here; but the essential values of self-control, purity and obedience to a bona fide spiritual master are just as necessary today as they were in Vedic times.
Srimad Bhagavatam Canto 11, Chapter 17, Text 22
Srimad Bhagavatam Canto 11, Chapter 17, Text 24