Vajrayudha

Vajra is a Sanskrit word meaning both thunderbolt and diamond. Additionally, it is a weapon won in battle which is used as a ritual object to symbolize both the properties of a diamond (indestructibility) and a thunderbolt (irresistible force).

The vajra is essentially a type of club with a ribbed spherical head. The ribs may meet in a ball-shaped top, or they may be separate and end in sharp points with which to stab. The vajra is the weapon of the Vedic rain and thunder-deity Indra, and is used symbolically by the dharma traditions of Buddhism, Jainism and Hinduism, often to represent firmness of spirit and spiritual power. The use of the vajra as a symbolic and ritual tool spread from India along with Indian religion and culture to other parts of Asia.

According to Asko Parpola, the Sanskrit Vajra- and Avestan Vazra- both refer to a weapon of the Godhead, and are possibly from the Proto-Indo-European root *weg'- which means "to be(come) powerful." It is related to Proto-Finno-Uralic *vaśara, "hammer, axe", but both the Sanskrit and Finno-Ugric derivatives are likely Proto-Aryan or Proto-Indo-Aryan, but not Proto-Iranian, state Parpola and Carpelan, because of its palatalized sibilant.

The earliest mention of the vajra is in the Rigveda, part of the four Vedas. It is described as the weapon of Indra, the chief among Gods. Indra is described as using the vajra to kill sinners and ignorant persons. The Rigveda states that the weapon was made for Indra by Tvastar, the maker of divine instruments. The associated story describes Indra using the vajra, which he held in his hand, to slay the asura Vritra, who took the form of a serpent.

On account of his skill in wielding the vajra, some epithets used for Indra in the Rigveda were Vajrabhrit (bearing the vajra), Vajrivat or Vajrin (armed with the vajra), Vajradaksina (holding the vajra in his right hand), and Vajrabahu or Vajrahasta (holding the vajra in his hand). The association of the Vajra with Indra was continued with some modifications in the later Puranic literature, and in Buddhist works. Buddhaghoṣa, a major figure of Theravada Buddhism in the 5th century, identified the Bodhisattva Vajrapani with Indra.

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