首楞嚴義疏注經 9.66

9.66

苦樂心滅，敵對則亡，形待既無，故云不交，不交則無煩也。初滅苦、樂二形待心，雜修初品，稍離定障，名為無煩，煩即障也。然下天亦離苦、樂不名無煩者，以凡夫人忻厭暫伏，非是永斷。今約畢竟不生，故得此名也。

When the minds of suffering and bliss are extinguished, opposition perishes; since mutual relativity is gone, it is said that 'they do not clash,' and not clashing means there is no affliction. When the two mutually relative minds of suffering and bliss are first extinguished, in the initial grade of mixed cultivation one slightly departs from the obstacles to concentration, which is called 'no affliction'—affliction being obstacle. However, the heavens below are also free from suffering and bliss yet are not called 'No Affliction' because ordinary beings only temporarily suppress them through revulsion and attraction, rather than severing them forever. Here, it is named in terms of their ultimately not arising.