Asahi sez:

A 2.3-centimeter gold-plated [copper] hand of Buddha was reported on the 10th of this month to have been discovered near the former site of Hinokuma Temple (檜隈寺) in Asuka, Nara. The shape of the hand, the purity of the copper, and other factors suggest that it was made in the 7th or 8th century C.E. (Asuka-Nara period), when [Japanese] gold-and-copper Buddha production was at its peak, but there is also a chance that it was imported.

The importers in the latter case would presumably be the Yamato no Aya clan (東漢氏), who themselves immigrated to Japan from Korea in the 4th century and are believed to have built the temple itself. (The "Aya", though written 漢 as in "Han Chinese", is commonly thought to signify an origin in Ara Gaya.)

As you can see, the hand itself has lost 60% of its digitry. A thumb and ring finger are enough for a kartari mudra, but it's a gruesome look. Also makes it hard to determine the iconographic type or even the size of the Buddha to which it was originally attached, apparently.

All that can be said for certain is that every night in Asuka village when the clock strikes twelve, the Buddha of Hinokuma shuffles silently through the streets with its bleeding stump held out before it. Meet not its gaze, traveler, an ye value those hands of your own.