仁王經疏 1.122

1.122

問：何故名解脫？答：如《婆沙》，棄背是解脫義。初二解脫棄背色貪心，第三解脫棄背不淨觀心，四無色解脫棄背下地心，想受滅解脫棄背一切有所緣心。

Question: Why are they called "liberations"? Answer: As in the Vibhāṣā, turning away and abandoning is the meaning of liberation. The first two liberations turn away from and abandon the mind of lust for form; the third liberation turns away from and abandons the mind of the contemplation of impurity; the four formless liberations turn away from and abandon the minds of lower stages; the liberation of the cessation of perception and feeling turns away from and abandons all minds that have an object.