俱舍論記 27.83

27.83

「如是靜慮至及實際言」者，釋第三章。如是靜慮得邊際名，此中邊名顯無越義。勝無越此定，故此定名邊。際言為顯類義，謂此定中有多種類相似義故，如說四際。謂一頌中四句分齊，或如一界四海分齊，皆是種類相似義也。或顯極義，如說金剛實際，或如說言諸法實際所謂涅槃，皆是極義。

Regarding the passage from "Such a dhyāna" up to "and the word bhūtakoṭi": this explains the third topic. Such a dhyāna obtains the name prāntakoṭika; here the word prānta expresses the meaning of having nothing beyond it (anuttara). No excellence surpasses this absorption, so this absorption is called prānta. The word koṭi is used to express the meaning of category (jāti), meaning that within this absorption there are many categories with similar meanings, as in the expression "four limits (koṭi)"—meaning the delimitation of four lines in a verse, or like the delimitation of the four oceans in a single realm, all of which are meanings of similarity in category. Alternatively, it expresses the meaning of the extreme/ultimate, as in speaking of the "adamantine real limit" (vajra-bhūtakoṭi), or as in the saying that the real limit of all dharmas is so-called nirvāṇa; these are all meanings of the ultimate.