Is it permissible to take school biscuits that were not distributed from a relative who sells or keeps them, and is it permissible to eat from them?

If a man trades in biscuits that rightfully belong to students, then it is impermissible to eat from them or accept them, and he must be advised and forbidden from doing so. However, if the taking was due to the absence of the students, then your permissibility to accept it depends on the permissibility of him taking it in the first place.