翻譯名義集 2.73

2.73

天界著樂，四趣沈苦，故此五道，非成佛器，由是諸佛唯出人間。如《智論》云：「若菩薩行般若者，從初發心，終不墮三惡道，常作轉輪聖王，多生欲界。何以故？以無色界無色故不可教化，色界中多味著禪定樂，無厭惡心故，亦不生。欲天妙五欲多，故在人中世世以四事攝眾生等。」故論誡曰：「三惡道眾生，不得修道業，既得此人身，當勉自利益。」覽此集者，宜警覺焉。

In the heavenly realms they are attached to pleasure, while in the four destitute paths they are sunken in suffering; thus these five destinies are not vessels for attaining Buddhahood, which is why all Buddhas appear only among humanity. As the Mahāprajñāpāramitopadeśa says: “If a bodhisattva practices prajñā, from the first generation of the aspiration he will never fall into the three wretched destinies, will constantly become a wheel-turning sage king, and will mostly be born in the desire realm. Why? Because the formless realm has no form and therefore cannot be converted, while in the form realm they mostly savor and are attached to the joy of meditative concentration and lack a mind of disgust, and thus he is not born there either. In the desire heavens, the fine five desires are abundant; therefore, remaining among humans, he gathers sentient beings life after life through the four means of embracing.” Hence the treatise admonishes: “Sentient beings of the three wretched destinies cannot cultivate the practice of the path; having obtained this human body, one should strive to benefit oneself.” Those who view this collection should take heed and be vigilant.