Arma Christi, or the Instruments of the Passion, are the objects associated with the Passion of Jesus Christ in Christian symbolism and art. They are seen as arms in the sense of heraldry, and also as the weapons Christ used to achieve his conquest over Satan. There is a group, at a maximum of about 20 items, which are frequently used in Christian art, especially in the Late Middle Ages. Typically they surround either a cross or a figure of Christ of the Man of Sorrows type, either placed around the composition, or held by angels.
The instruments of the Passion. Left to right: the cross of the penitent thief Dismas, ladder, sponge on reed, hammer, angels, Cross of Christ, cock, star, pincers, ladder, spear, cross of the wicked thief Gestas, and two hyssop plants growing from the ground (église Saint-Pierre de Collonges-la-rouge).
The instruments of the Passion (cont). Left to right: chalice, torch, lantern, sword, flagellum, pillar of flagellation, Veronica's veil, 30 pieces of silver, dice, reed sceptre, hand which struck Christ, torch, pitcher of gall and vinegar.
Pietà with Arma Christi, Lorenzo Monaco, 1404
Relics that are claimed to be the Holy Nails with which Jesus was crucified are objects of veneration among some Christians, particularly Roman Catholics and the Eastern Orthodox. In Christian symbolism and art, they figure among the Arma Christi or Instruments of the Passion, the objects associated with the Passion of Jesus. Like the other Instruments, the Holy Nails have become an object of veneration among many Christians and have been pictured in paintings.
Holy Nail reliquary in the Treasury of Trier Cathedral
Angel Holding the Holy Nails, formerly one of a series of "Angels of the Passion", oak, formerly painted, Northern French, late 13th century (Metropolitan Museum of Art)
Holy Nail in Santa Maria della Scala in Siena