英文諺語(yǔ):有眼不識(shí)泰山

Entertain an angel unawares.
     有眼不識(shí)泰山
     Explanation： to receive a great personage as a guest without knowing his merits.
     Example： in the course of evening someone informed her that she was entertaining an angel unawares， in the shape of a composer of the greatest promise