Garudapurana 1.213.14

1.213.14

triḥ snātā snāpitā bhaikṣyaṃ gurau prāṇāntikī sthitiḥ /
samekhalo jaṭī daṇḍī muṇḍī vā gurusaṃśrayaḥ //

Bathing thrice, bathing [the teacher], begging food, remaining with the guru until the end of life, / wearing a girdle, matted hair, carrying a staff, or shaven-headed, taking refuge in the guru;