仁王護國般若經疏 2.31

2.31

問：解脫以何為義？答：解脫以棄背為義。初二棄背色貪心，第三棄背不淨觀心，四無色棄背下地心，滅盡令棄背一切所有緣心。

Question: What is the meaning of liberation? Answer: Liberation takes turning away from and abandoning as its meaning. The first two turn away from and abandon the mind of craving for forms; the third turns away from and abandons the mind of contemplation on impurity; the four formless [absorptions] turn away from and abandon minds of lower stages; cessation causes one to turn away from and abandon all minds conditioning existent things.