it'll all come out in the wash

1. No permanent or lasting effects will occur as a result; things will normalize over time. I wouldn't worry too much about processing the invoice incorrectly; I'm sure it'll all come out in the wash. A: "Do you think Mark hates me after what I said at the party?" B: "Nah, it'll all come out in the wash." Don't worry about paying me back for dinner. It'll all come out in the wash eventually.

2. A lie or other secret will be uncovered eventually. Whatever the mayor is trying to cover up, it'll all come out in the wash. You can only hide an affair for long. Stuff like that, it'll all come out in the wash sooner or later. It'll all come out in the wash once this goes to court, so then we'll find out what really happened.

it will all come out in the wash

Everything will be settled satisfactorily. This term, which alludes to the removal of dirt and stains by laundering, originated in Britain in the late nineteenth century, although a version of it occurred in Cervantes’s Don Quixote (1605): Todo saldrá en la colada (“All will come out in the laundry”). “It all goes into the laundry, but it never comes out in the wash,” wrote Rudyard Kipling (Stellenbosh, 1881).