Wash your hands of somebody/something
Definition 1 of 1
Pro Tip 1/3Metaphorical Cleanse
Imagine washing dirt off your hands to feel the sense of removing something undesired or troublesome. 
After quitting the toxic job, I felt like I washed my hands of a great burden.
Pro Tip 2/3Not Always Negative
The phrase can be neutral, not implying that the person or thing is bad, but that you no longer wish to be involved. 
She washed her hands of the project, trusting her team to handle it.
Pro Tip 3/3Emotionally Charged
Using this phrase can show strong emotions such as frustration or relief after distancing oneself. 
He washed his hands of his old friend's problems, feeling a mix of guilt and liberation.