成唯識論了義燈 7.115

7.115

三、二障現行名為麁重，即說惛沈正障輕安，違細輕故，名為麁重，如第六明。又《對法》第十云：領受麁重，即異熟受，能障定故。

Third, the active manifestations of the two obscurations are called coarse heaviness; that is, torpor directly obstructs pliancy (praśrabdhi), and because it opposes what is subtle and light, it is called coarse heaviness, as explained in the sixth fascicle. Furthermore, the Abhidharmasamuccaya fascicle ten states: Experiential coarse heaviness, which is vipāka sensation, because it can obstruct concentration.