李卓吾先生批評西遊記 (Journey to the West), Vol. 1

What proof is there of not attaining the Way? If one is not satisfied and must ask about the mysterious mechanisms original: "玄機" in the Jade Casket original: "玉函", a reference to secret Daoist texts, or search for the Zen stamen in the Dragon Treasury original: "龍藏", the Buddhist canon, only then will one have an attainment.