phrase, origin of which is in Hebrew and now is probably the most popular phrase in Israel. It's equivalent to "leave me alone" but carries a kind of sarcastic meaning. it's usually used when someone proposes to you something and you just refuse because it either doesn't interest you or you just don't care.
Additionally, "In your mother" is short for "Swear in your mother", an Hebrew common to "Swear to god". Two-three decades ago, for example, the common was "swear to your most precious". "Swear to god" is not in use for obvious reasons.
Used in place of 'shit' by people trying to quit their bad habbit of swearing, or when a person feels that they are too pure to swear.
Has the compounded benefit of rhyming with the swear word 'Christ'