大乘百法明門論開宗義決 1.151

1.151

Regarding "abiding in equality, uprightness, and effortless application": "equality" explains the initial stage of equanimity. Because equanimity causes the mind to be separated from unequal states such as depression and agitation, one first realizes the equal nature of the mind. "Uprightness" explains the middle stage of equanimity. Further, because of equanimity, the equal mind is kept distant from exertion and continues naturally; next, one realizes the upright nature of the mind. "Abiding in effortless application" explains the later stage of equanimity. Further, because of equanimity, the upright mind has no dread or anxiety regarding defilements; lastly, one realizes the nature of abiding in effortless application. Possessing these three meanings distinguishes it from the feeling of equanimity among the three feelings; hence it is called formative equanimity.