俱舍論頌疏論本 24.29

24.29

釋曰：若在聖位經欲界生，厭欲界生，厭苦心強，必不往上色、無色界，證不還已，定於現身般涅槃故。若於色界經生聖者，容有上生無色界義，色界無苦，厭心劣故，容生無色天。此經欲界生聖及往上界生聖必無練根，兼無有退。問：「何緣經生聖及上生聖必無練根並退？」答：「經生習根極淳熟故，及得殊勝所依止故（昔於凡身得道，未名勝依，經生唯於聖身，名殊勝之也），故無練根及退轉也。」

The explanation says: If one in a noble state undergoes rebirth in the desire realm, being disgusted with rebirth in the desire realm, their mind of disgust toward suffering is strong, and they definitely do not go to be reborn above in the form or formless realms; having realized non-returning, they definitely attain parinirvāṇa in the present life. If a noble one has undergone rebirth in the form realm, it is possible for them to be reborn above into the formless realm, because there is no suffering in the form realm, their mind of disgust is weak, and so it is possible to be reborn in the formless heavens. These noble ones who have undergone rebirth in the desire realm and noble ones who go to be reborn in higher realms definitely have no refinement of faculties, and additionally have no falling back. Question: "For what reason do noble ones who have undergone rebirth and noble ones reborn above definitely have neither refinement of faculties nor falling back?" Answer: "Because through undergoing rebirth their faculties have been practiced to extreme maturity, and because they have obtained an excellent support (formerly when attaining the path in an ordinary person's body, it was not yet called an excellent support; having undergone rebirth solely in a noble one's body, it is called an excellent one), they therefore have neither refinement of faculties nor falling back."