Manava Dharmashastra 2.184

2.184

guroḥ kule na bhikṣeta na jñātikulabandhuṣu
alābhe tv anyagehānāṃ pūrvaṃ pūrvaṃ vivarjayet //

Let him not beg from the relatives of his teacher, nor from his own or his mother's blood-relations; but if there are no houses belonging to strangers, let him go to one of those named above, taking the last-named first;