成唯識論述記 6.187

6.187

述曰：此證苦俱。又地獄全鬼畜，少分純受苦處，如前已說。意有苦受，亦希求解脫。解脫者，解脫彼苦，故欲、苦俱。

The Commentary states: This proves association with suffering. Furthermore, in the hells entirely, and in parts of the ghost and animal realms—in realms of pure suffering—as was explained earlier, the mental consciousness has the feeling of suffering and also seeks liberation. Liberation means being freed from that suffering; hence desire and suffering associate.