What's the difference between forefend and forfend?

Forefend

Definition:

(v. t.) To hinder; to fend off; to avert; to prevent the approach of; to forbid or prohibit. See Forfend.

Example Sentences:

(1) Lord Smith, the chairman of the ASA and former Labour culture secretary, said "heaven forefend" that an opportunity is opened up to "create a Fox News in the UK".

Definition:

Example Sentences:

(1) And also, heaven forfend, if you want to unsubscribe.
(2) (Heaven forfend some black lady should be in the dressing room, right?
(3) Instead, their smaller stores have enabled us to make shopping for food a small part of some other excursion – to meet a friend for a drink, walk the dog, go to the hairdresser or the gym, go – heaven forfend – to the butcher, the baker or the candlestick maker as well.
(4) If (heaven forfend) the politicians of your side ever disappoint you, that is even more a reason to stay in the conversation, rather than leave it.
(5) It has fallen to Pius XII to denounce Communist ideology in such an implacable manner as to forfend a series of schisms on the part of Catholics tempted to yield to Communist blandishments.
(6) Heaven forfend that this be taken as either a gimmick or a giveaway: the chancellor had made a self-denying ordinance against both.
(7) School children would have to leave their seats and, heaven forfend, talk to each other during lessons.