God forbid!

God forbid!

 and Heaven forbid!
a phrase expressing the desire that God would forbid the situation that the speaker has just mentioned from ever happening. Tom: It looks like taxes are going up again. Bob: God forbid! Bob: Bill was in a car wreck. I hope he wasn't hurt! Sue: God forbid!
See also: god
References in classic literature ?
Do not talk to me, then, any more of the respect you owe the king, and be careful of your words, that they may not chance to convey the slightest menace; for the king will not allow those to be threatened who do him service by others who do him disservice; and if in case I should have, which God forbid
Could it be that the same God will send Tony Blair and his troops on such a divine mission to Tehran - God forbid
On top of all this, they want to spend millions on a new building for themselves - God forbid