《逸周书·卷五·武儆解》
十二年四月，武王告人他作了恶梦，并命令周公给他立后嗣。丙辰日，拿出铸在铜版上的《郊宝》和写得细密的 《开和》，讲给太子姬诵，又讲到了《宝典》。
惟十有二祀四月，王告梦，丙辰，出金枝，郊宝，开和细书，命诏周公旦立后嗣，属小子诵文及宝典。
In April of the twelfth year, King Wu told people that he had a nightmare and asked Duke of Zhou to establish a successor for him. On the day of Bingchen, he took out the "Suburb Treasure" cast on a bronze plate and the "Kaihe" written in detail, and told it to Prince Ji Song, and also mentioned the "Treasure Code."