首楞嚴義疏注經 9.81

9.81

In Sanskrit they are called anāgāmin, which here means 'non-returning'. Because these heavens are the dwelling place of those noble ones, they are also called the Pure Abodes; they are not the residences of ordinary beings with outflows. Through the pre-eminence of their samādhi power, their environmental reward is likewise pre-eminent; though dwelling in the same world, their realms are distinct, as is understood by the analogy given.