‘I’ll tell you God’s truth.’ His right hand suddenly ordered divine retribution to stand by. ‘I am the son of some wealthy people in the Middle West all dead now. I was brought up in America but educated at Oxford, because all my ancestors have been educated there for many years. It is a family tradition.’
– F. Scott Fitzgerald
The Great Gatsby, Chapter 4. Jay Gatsby raises his right hand and invokes God’s retribution if he is lying. Which is course he is, having invented the illusion of coming from old money and being a highly educated Oxford man.