大乘義章 11.79

11.79

次論主伴。如龍樹言「慈為如王，餘三隨從如民隨王。」慈心正是與樂之意，故說為主。無悲拔苦，與樂不成，故悲隨慈。無喜除嫉，與樂不勝，故喜隨慈。無捨除礙，與樂不等，故捨隨慈。蓋乃只據一門為論。理實四行皆得為主、齊得為伴，互相隨故。

Next, discussing primary and secondary. As Nāgārjuna says: 'Benevolence is like a king; the other three follow along like subjects following a king.' The mind of benevolence is precisely the intention to give joy, so it is said to be primary. Without compassion to eradicate suffering, giving joy cannot be accomplished, so compassion follows benevolence. Without sympathetic joy to eliminate envy, giving joy is not superior, so sympathetic joy follows benevolence. Without equanimity to remove hindrances, giving joy is not equal, so equanimity follows benevolence. This is merely discussed based on one perspective. In actuality, all four practices can be primary and can equally be secondary, because they follow one another.