(one's) number comes up

One is selected for something by chance or at random, whether it be fortunate or unfortunate. All I heard were horror stories about the war in Vietnam. I'm not too proud to admit that when my number came up to serve, I very nearly absconded to Canada. He scans the lottery results every day to see if his number has finally come up.

your/somebody’s (lucky) ˈnumber comes up

(informal) somebody is very lucky in a competition, etc: If my lucky number comes up, we’ll spend a weekend in Venice.