An
agreement of sale which is unlawful in respect of its substance
and description. For example, an agreement of sale concluded by
a lunatic or a minor is batil since it does not possess
the substance of the agreement which is the proposal and
acceptance by a sane or major person. Similarly, an agreement to
sell a dead body or alcohol is not lawful since it involves
exchange of mal for something valueless (ghair mutaqawwam).
