Srimad-Bhagavatam: Canto 7 - Chapter 1 - Verse 2
Sanskrit:
बिभृयाद् यद्यसौ वास: कौपीनाच्छादनं परम् ।त्यक्तं न लिङ्गाद् दण्डादेरन्यत् किञ्चिदनापदि ॥ २ ॥
ITRANS:
bibhṛyād yady asau vāsaḥkaupīnācchādanaṁ paramtyaktaṁ na liṅgād daṇḍāderanyat kiñcid anāpadi
Translation:
A person in the renounced order of life may try to avoid even a dress to cover himself. If he wears anything at all, it should be only a loincloth, and when there is no necessity, a sannyāsī should not even accept a daṇḍa. A sannyāsī should avoid carrying anything but a daṇḍa and kamaṇḍalu.