俱舍論記 20.16

20.16

「謂眼及色至應闕二緣」者，答。六根、六境各生自識名曰二緣。若去、來世非實有者，能緣過去、未來意識應闕二緣。過去無故，應闕依、緣。過、未無故，應闕境緣。

Regarding "Namely, eye and forms ... would lack the two conditions": this is the reply. The six sense-faculties and the six sense-objects each produce their own consciousness, which is called the "two conditions". If past and future periods were not substantially existent, the mental consciousness taking the past and future as objects would lack two conditions. Because the past would not exist, it would lack support and condition. Because past and future would not exist, it would lack the objective condition (ālambana-pratyaya).