俱舍論頌疏論本 29.7

29.7

緣欲界有情者，明所緣境，此四無量普緣欲界一切有情。不緣上界者，謂能治彼瞋等障故，上界無瞋等故，不緣上界也。

"[They] take sentient beings of the desire realm as their object" explains the objective sphere: these four immeasurables generally take all sentient beings of the desire realm as their object. They do not take the higher realms as their object because they act as antidotes against hindrances such as malice belonging thereto; since the higher realms are free from malice and the like, they do not take the higher realms as their object.