俱舍論頌疏論本 10.49

10.49

初無色近分，緣色四自一者，謂空處近分唯繫四種，緣色界境亦有四種，謂空處近分起有漏道，能緣色界第四靜慮色等四境，既緣有四，繫亦四也。緣自界一，謂唯法境。

Regarding "the preliminary stage of the first formless [realm] has four cognizing the form [realm] and one its own": the preliminary stage (sāmantaka) of the sphere of infinite space is bound to only four kinds, and in cognizing objects of the form realm it also has four kinds; that is, the preliminary stage of the sphere of infinite space gives rise to the contaminated path, which can cognize the four objects such as form of the fourth dhyāna in the form realm. Since it cognizes four, its bonds are also four. Cognizing its own realm has one: solely the object of dharmas.