俱舍論頌疏論本 10.50

10.50

四本及三邊，唯一緣自境者，謂空處等四根本地及識處等三近分地，名為三邊，此七地中唯一，謂法。無色根本不緣色界，彼上三邊亦不緣色，故唯有法一近行也。不緣色義，定品當辨。

Regarding "the four fundamental and three thresholds have only one, cognizing their own sphere": the four fundamental stages (maula) of the sphere of infinite space and so forth, and the three preliminary stages of the sphere of infinite consciousness and so forth, are called the "three thresholds"; in these seven stages there is only one, namely dharmas. The fundamental formless [dhyānas] do not cognize the form realm, and their higher three thresholds also do not cognize the form realm, hence they have only the one exploration of dharmas. The meaning of not cognizing form will be analyzed in the Chapter on Samādhi.