leave someone to their own devices
leave (one) to (one's) own devices
To let one rely on oneself, without any help or other interference. I'm going to leave you to your own devices and see what you come up with without my input. It's amazing how some kids can really thrive when you leave them to their own devices, while others will be completely helpless.
leave someone to their own devicesleave someone to do as they wish without supervision.
Device in the sense of ‘inclination’ or ‘fancy’ now only occurs in the plural, and is found only in this expression or in the phrase devices and desires , as quoted from the General Confession in the Book of Common Prayer.