From Longman Dictionary of Contemporary Englishthrow yourself on somebody’s mercythrow yourself on somebody’s mercyFORGIVEto ask someone to help you or forgive you when you are in a very bad situation → mercy
Examples from the Corpus
throw yourself on somebody’s mercy• For a craven moment she was tempted to go back and throw herself on the mercy of the landlady.• You're so sweet I just wanted to throw myself on your mercy and beg you to help me.• I would throw myself on the mercy of the circuit-house, usually reserved for traveling politicians and sundry bigwigs. 