Manava Dharmashastra 2.200

2.200

yatra deśe durjanasampāte guroḥ parīvādaḥ sambhūtadoṣānukathanam nindā avidyamānānāṃ doṣāṇāmabhidhānam, pravartate tatra karṇau vidhātavyau aṅgulyādinā saṃvarītavyau | tataḥ pradeśādvā'nyatra gantavyam |

Medhātithi’s commentary (manubhāṣya):
‘When the teacher has his face averted,’—the pupil should sit facing him; that is, if the Teacher happen to have his face turned the other way when he gives his directions, the pupil should go over to the side facing the teacher and then do the aforesaid (listening and conversing).