All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
We have already clarified in Fataawa 115236, 86185 and 81709 that cheating in exams is forbidden as well as helping others to do so. If this is done by a teacher, then this is even more abominable and more sinful. This is because the teacher is entrusted with watching the students during exams, so his doing this is a betrayal of trust, and this is a characteristic of the hypocrites.
In addition, the teacher should set a good example to the students, so how come he does such evil matters with them and in front of them?
Nonetheless, the teacher asking them to supplicate for him is in principle permissible, unless this is done out of mockery.
Besides, a student saying to his classmate “Help me, Allaah will help you on the Day of judgment,” while meaning cheating by this expression, and while knowing that it is cheating, is evidence of ignorance, heedlessness and carelessness regarding committing sins; otherwise, the recompense (for a deed) is of the same kind as the deed itself, so, whoever does an act of disobedience, such as cheating and so forth, is obliged to repent to Allaah.
Allaah Knows best.