大乘入道次第開決 1.121

1.121

以無所得行相思惟等者。謂觀自他身無身相。而不見有淨與不淨。而修對治身妄念也。受及心法亦如是說。

Regarding "contemplating with the mental mode of non-apprehension": this means observing that the bodies of self and others lack the characteristic of a body, and not seeing purity or impurity, thereby cultivating the antidote to erroneous mindfulness of the body. Feeling, mind, and dharmas are also explained in this way.