I thought it was due to median n. lesion.
IE. tell somene to make a fist (they flex digits 4 and 5 due to flexor digitorum profundus being intact (the lateral two bellies inn. by ulnar n.).) Thus the first three digits are extended, also the pollicis is pulled in due to an intact adductor pollicis and loss of opponens pollicis...thus "hand of benediction" first three digits extended and last two clawed (upon telling someone to make a fist).