Hobbes: What’s the difference between a gift and a contract?

Hobbes starts with a broad definition of a “right” as “the liberty each man hath to use his own power, as he will himself, for the preservation of his own nature” (79). From this, a contract is a “mutual transfer” of this right between men. But, distinct from a contract is a free-gift, as this is a “not mutual” transfer.

But is it not true that the acceptance of a free-gift implies a mutual agreement between both parties? Just as both parties opt into a contract, both parties opt into a free-gift. The giver will only offer a free-gift if the “friendship or service” or “magnanimity” he may receive is in his own self-interest (82). The recipient will only accept the free-gift if possession of it benefits his own self-interest. Neither has entered the transfer until both have consented to it, and both will only consent to it if it is in their own self-interest. Therefore, the transfer is mutual.

By this definition, Hobbes assumes that all free-gifts will be accepted. But what if accepting a free-gift is not in my self interest? If the debt of friendship or service that I owe to the gifter is not in my self interest, it is by the nature of man that I do not consent to the transfer, and the transfer never occurs. 

I do suppose, however, it can be argued that a free-gift does not need to be accepted. But is it possible to force a right upon someone against their will? Is that what a free-gift is? This then becomes a question of at which point in time does the transfer of a gift take place. For example, does leaving an Edible Arrangement on my porch constitute a transfer, or has it only been gifted when I pick it up to take it inside? I do not find that Hobbes clearly defines this.