hold your thumbs
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.
hold your thumbsfold 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.