瑜伽論記 7.463

7.463

於中兩番，初番中，怯弱障者，謂於涅槃出離法及於世出世道遠離之法勤修行時，於雜染法有戀慕不樂希望憂惱，故心怯弱。

Within this there are two cycles. In the first cycle, the 'obstacle of faintheartedness' means that when one diligently cultivates the dharmas of renunciation leading to nirvāṇa and the dharmas of seclusion belonging to the mundane and supramundane paths, one harbors longing, dissatisfaction, longing expectation, and grief regarding defiled dharmas; therefore, the mind becomes fainthearted.