Wiktionary
heaven forfend
interj. To say that one hopes that something does not happen.
Usage examples of "heaven forfend".
The prior, however, hath so ordered that while he holds this cross no man may lay hand upon him without the ban of church, which heaven forfend from me or mine.
Black Mango concealed now, her own unnameable names still warm upon her lips, she cried, 'Heaven forfend!