俱舍論記 11.24

11.24

「如是九山至出水量同」者，明其九山高、廣二量，入水皆等、出水半半，卑廣與出水同。思之可解。

"The nine mountains in this way […] equal in the amount emerging from the water": this explains the height and breadth of the nine mountains; the depth submerged in water is equal for all, while the height emerging from water halves sequentially, with the lower breadth equal to the height emerging from water. This can be understood by contemplating it.