Expressing a skeptical affirmative, to indicate the unlikeliness of events, as if they need a divine intervention to come about.
Expressing the speaker’s wish for a given future event to occur and/or their emphasis on its contingency upon the divine will.
Hopefully; a self-directive to undertake the customary action to ward off bad luck.
To take a customary action to ward off some misfortune that is believed to be attracted by a presumptuous statement.