expression, godan verb (-su)
be possessed by an evil spirit; be tempted; give in to an urge
Describes a momentary lapse in judgment or self-control, as if an evil spirit made one do something wrong. Often used for sudden, uncharacteristic misdeeds or yielding to temptation.
つい魔が差して、人の物を盗んでしまった。
I was momentarily tempted and ended up stealing someone's belongings.
魔が
I gave in to temptation and ate cake even though I'm on a diet.