Wondrous item, common
Set the hand on a firm surface and name a kind of thing — coins, sacks, tiles, arrows, casks, lots, persons. As an action, the hand counts every such thing in plain sight within 60 feet, up to a thousand, and the count is exact; the fingers work for a round and stop, and you read the number off the bone plates. It counts nothing it cannot see: a closed box counts as one box.
The plates hold the last nine counts until a tenth pushes the oldest out. The hand cannot be made to count wrong by illusion, disguise, or a creature's efforts to conceal itself: a hidden or invisible thing standing in plain space is counted, though the hand gives no clue where it stands.
It makes no distinction between things and persons, and it does not stop at a number it has given before. Set twice within the hour before the same shelf of this hall, it has given two numbers. The hand was afterwards taken down and opened at the bench, and was found sound, complete, and clean.
Source: Provenance — The Quist Sale