hold (one's) thumbs

To maintain hope that something will happen or be the case. Can be accompanied by a gesture in which one literally brings one's fingers down over the thumb. Primarily heard in South Africa. The team's manager will be holding thumbs that his star player will be healthy enough to play on Saturday. I hope we get the account, but don't hold your thumbs. If you didn't study for the test, I wouldn't hold your thumbs for a good grade.

hold ˈthumbs

(South African) hope that your plans will be successful or that something will take place in the way that you want it to: Let’s hold thumbs that you get the job.