Bulbokjang (佛腹藏) refers to sacred objects stored inside Buddhist images. This tradition is known to have originated in the Goryeo dynasty. This practice is verified in a number of sources of the Goryeo dynasty: the Naksan gwaneum bokjang subomun byeongsong (洛山觀音腹藏修補文幷頌, Record and praise for repairing an Avalokiteśhvara at Naksansa by re-stocking objects inside it) by Yi Gyubo ( 李奎報, 1168-1241), the Gukcheongsa geumdang jubul seokgayeorae sari youngigi ( 國淸寺金堂主佛釋迦如來 舍利靈異記, Record on the numinous relics of the Śākyamuni Buddha in the golden hall of Gukcheongsa) by Min Ji ( 閔漬, 1248-1326), and the Seogwangsa dangju birojana jwaubocheo munsu bohyeon bokjang ( 釋王寺堂主毗盧遮那左右補處文殊普賢腹藏; Storing objects inside the Buddha Vairocana and the bodhisattvas Mañjuśrī and Samantabhadra of Seogwangsa) by Gwon Geun ( 權近, 1352-1409). The objects enshrined in Buddhist statues and their significance were described in detail in the above sources. It suggests that the Goryeo people considered the magnificence of the Buddha statues as well as the rite of placing objects inside the statues as being highly important. They believed the act of inserting objects inside the Buddhas would accrue virtuous deeds and produce miracles. Approximately ten sets of sacred objects have been so far discovered in Buddhist statues of the Goryeo period.