成唯識論了義燈 7.136

7.136

又解：二障各分上下，麁、細難、易斷差別故。如佛十力，根上、下力，中根隨應，屬上、下故，斷障亦爾。中品隨應，由觀行者意樂力故。隨上下斷，故各分二。

Another interpretation: The two hindrances are each divided into higher and lower, on account of the differences between coarse and subtle, difficult and easy to sever. Just as in the ten powers of a Buddha, the power regarding superior and inferior faculties has medium faculties subordinate to the superior or inferior according to circumstance, the severance of hindrances is also like this: the medium grade, according to circumstance, is severed along with the superior or the lower through the force of the practitioner's intention; therefore each is divided into two.