fall into your lap
fall into (one's) lap
To be received unexpectedly or without effort. I didn't steal the internship from you—it fell into my lap, I swear! Your aunt has decided to get a new car, so her old one might fall into your lap.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
fall into your lapor
drop into your lap
If something good falls into your lap or drops into your lap, you get it without making any effort. Note: In the first four idioms, `lap' refers to the area at the top of your thighs when you are sitting down, where a child would sit. She doesn't really know what to do with the large cheques that regularly fall in to her lap. It would not be safe to assume that victory will drop into our lap at the next election.
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012