首楞嚴義疏注經 9.42

9.42

Fourth, as for the fourth dhyāna, the general retribution karma of this single ground has only three grades, which produce the lower three heavens. The Heaven Without Thought is merely an individual retribution within the Heaven of Vast Fruits, and the realm of ordinary beings reaches its peak here. The Five Non-Returning Heavens, however, are where noble ones cultivate mixed meditations to reinforce the past karma of the Heaven of Vast Fruits, making five grades of superiority; they are born in those five heavens simply from the general retribution body of the Vast Fruits Heaven, which differs from ordinary beings. Because of this, it forms a separate section below.