hold (one's) thumbs
To maintain hope that something will happen or be the case. 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.
hold your thumbs
fold your fingers over your thumbs to bring good luck; hope for luck or success. South African 1987 Sunday Times (South Africa) They say they are holding thumbs for her and praying that the pregnancy will be trouble-free.