大般涅槃經疏 17.9

17.9

From 'Good son, for the sake of all sentient beings' onward, this is the second, explaining the combined function of friendliness: if friendliness only gave happiness and compassion only eradicated suffering, then that would not be combined function. Now it explains that friendliness also eradicates suffering, and compassion also gives happiness. Within equanimity there are also two, as in the text.