While the offer may bind a person morally, since the offer has not been created with any consideration, it is gratuitous and treated as a unilateral contract. The offer is therefore revocable at any time by the offeror before acceptance by the offeree.
While the offer might have moral binding power, since it lacks consideration, it is gratuitous and considered a unilateral contract. Therefore, the offer can be revoked at any time by the offeror before acceptance from the offeree.