1
general::
Unexpected good fortune, a windfall, as in They sent back our check? pennies from heaven. This expression may have originated with a song and motion picture so named (1936), popularized by Bing Crosby. In addition to the idioms beginning with PENNY, Also see IN FOR A PENNY, IN FOR A POUND; PINCH PENNIES; PRETTY PENNY; TURN UP (LIKE A BAD PENNY).
American Heritage Idioms