妙法蓮華經玄贊 6.261

6.261

贊曰：此釋所由。有二：一道已滿，無苦心安；二年已邁，齒過力屈。故於大法既非己望，無一樂心。

The Commentary says: This explains the reasons. There are two: 1. the path was already fulfilled, free of suffering and with their minds at ease; 2. their years were already advanced, past their prime and declining in strength. Therefore, since the Great Dharma was not what they anticipated, they did not have a single thought of delight.