成唯識論演祕 2.484

2.484

即是彼天第六識等種子之上。能遮彼地六識等現不起功能。名為無想異熟體也。

This is simply the capacity, existing upon the seeds of the sixth consciousness and so forth of that heaven, to block the active manifestation of the six consciousnesses and so forth of that plane from arising, which is named the entity of the non-conception maturation.