成唯識論述記 7.296

7.296

述曰：自下第三文第七地繫。彼第四定方便引故，唯彼繫攝，何故唯在第四靜慮，說此果所以？即說定所由，如前說故。如又《毘婆沙》一百五十二有二定依地之義大廣。

The Commentary states: From here down is the third text, the seventh [meaning]: the realm to which it is bound. Because it is induced by the expedient means of that fourth dhyāna, it is exclusively bound to and included in that realm. Why is it only in the fourth dhyāna? In explaining the reason for this fruit, it directly explains the reason for the attainment, as stated previously. Furthermore, fascicle one hundred fifty-two of the Vibhāṣā has a very extensive explanation of the meaning of the supporting grounds of the two attainments.