俱舍論疏 5.232

5.232

論「若行離生相至何故不生」，有部難經部也。有為、無為俱無生相。有為既生，無為何為不生？

The Śāstra states: "If conditioned formations are apart from the mark of arising... why do they not arise?" The Sarvāstivādin challenges the Sautrāntika: both conditioned and unconditioned dharmas lack the mark of arising; since conditioned dharmas arise, why does the unconditioned not arise?