俱舍論疏 6.13

6.13

論「若於此生至可立為因」，難也。若先能障，由今不障，可得是因。本無障力，今不為障，何得是因？

The Śāstra says, “If, when this arises... it can be established as a cause,” which is an objection. If it was previously capable of obstructing and now does not obstruct, it can be a cause. But if it originally lacked the power to obstruct and now does not obstruct, how can it be a cause?