leave one to 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.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
leave one to one's own devicesand leave one to one's own resources
Fig. to make one rely on oneself.—I am sure that she will manage if we leave her to her own devices. I will leave her to her own resources and everything will turn out fine.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.