Srimad-Bhagavatam: Canto 7 - Chapter 1 - Verse 4
मेखलाजिनवासांसि जटादण्डकमण्डलून् ।बिभृयादुपवीतं च दर्भपाणिर्यथोदितम् ॥ ४ ॥
mekhalājina-vāsāṁsijaṭā-daṇḍa-kamaṇḍalūnbibhṛyād upavītaṁ cadarbha-pāṇir yathoditam
Carrying pure kuśa grass in his hand, the brahmacārī should dress regularly with a belt of straw and with deerskin garments. He should wear matted hair, carry a rod and waterpot and be decorated with a sacred thread, as recommended in the śāstras.