SB 7.12.1

śrī-nārada uvāca
brahmacārī gurukule
 vasan dānto guror hitam
ācaran dāsavan nīco
 gurau sudṛḍha-sauhṛdaḥ
Word for word: 
śrī-nāradaḥ uvāca — Śrī Nārada Muni said; brahmacārī — a brahmacārī, a student living at the residence of the guru; gurukule — at the residence of the guru; vasan — by living; dāntaḥ — continuously practicing control of the senses; guroḥ hitam — only for the benefit of the guru (not for one’s personal benefit); ācaran — practicing; dāsa-vat — very humbly, like a slave; nīcaḥ — submissive, obedient; gurau — unto the spiritual master; su-dṛḍha — firmly; sauhṛdaḥ — in friendship or good will.
Translation: 
Nārada Muni said: A student should practice completely controlling his senses. He should be submissive and should have an attitude of firm friendship for the spiritual master. With a great vow, the brahmacārī should live at the gurukula, only for the benefit of the guru.