Isho was prepared as shichi-i, corresponding to the shichi-kei, which added the Book of Filial Piety to Rikkei, and along with its prophecies, shin-sho (prophecy) and Toshin (prediction, prophecy), it was called Shini, and became popular from the end of former Han to later Han.
緯書は六経に孝経を足した七経に対して七緯が整理され、予言書である讖書や図讖（としん）と合わせて讖緯といい、前漢末から後漢にかけて流行した。