瑜伽論記 6.368

6.368

三藏云：佛於長行略說未顯名未了義，故於中間或於最後重說伽陀令顯了，故云或復宣說未了義經，亦未論要，為後來或為鈍根方重說。

The Tripiṭaka Master says: The Buddha expounded briefly in prose without making it fully explicit, which is called 'not fully understood meaning'; therefore, in the middle or at the very end, he repeated verses to make it explicit; hence it is said, 'or again, expounding sūtras of implicit meaning.' It is not yet the essential treatise, but verses repeated only for latecomers or for those of dull faculties.