Rock kalpa

rock kalpa
磐石劫 (Jpn banjaku-go)

    Also, rock-rubbing kalpa. One of several definitions of a kalpa used to illustrate its measureless length. According to The Treatise on the Great Perfection of Wisdom, a kalpa is longer than the time required to wear away an immense cube of rock forty ri (one ri is about 450 meters) on each side if one were to brush it with a piece of cloth once every hundred years. In the Miscellaneous Agama Sutra, the length of each side of the rock is given as one yojana (about 7 kilometers)

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