leave (someone or something) in (one's) hands
To allow one to have control, authority, or responsibility over someone or something. We're leaving the kids in my mother-in-law's hands while we're in Barcelona. I'm getting too old to run this business anymore, Jake—I'm ready to leave it in your hands.
leave someone or something in one's hands
Fig. to give one control of or responsibility for someone or something. You left the whole project in my hands! I have to leave the care of baby in your hands while I go to the doctor.