swear on (one's) mother's grave

swear on (one's) mother's grave

To make a very serious, solemn pledge, especially that one is telling the truth. Janet has sworn on her mother's grave that she wasn't the one to betray me, and I believe her. I swear on my mother's grave that if I have a chance to help your campaign, I will.
See also: grave, on, swear
Farlex Dictionary of Idioms.
See also:
  • 1FTR
  • drive (one) out of office
  • force (one) out of office
  • force out of office
  • give (one) (one's) head
  • give head
  • give somebody their head
  • give someone their head
  • cooking for one
  • as one door closes, another opens