俱舍論疏 5.136

5.136

論「壽盡位中至俱盡故死」，釋伏難也。能感二種業俱盡時此死，由感壽業盡死，豈由福盡令命死耶？解云：福盡於死雖無功力，以死之時二俱時盡，由斯但言俱盡故死。此俱盡言，不欲說由福盡力也。

The treatise says: "At the time of the exhaustion of life, up to: death due to the exhaustion of both." This resolves an implicit objection: When both karmas capable of projecting [life and merit] are exhausted, this death is due to the exhaustion of the karma projecting life; how could exhaustion of merit cause life to perish in death? It is explained: Although the exhaustion of merit has no efficacy regarding death, because at the time of death both are exhausted simultaneously, on this account it is merely said to be 'death due to the exhaustion of both.' This phrase 'exhaustion of both' does not intend to say that it is through the power of the exhaustion of merit.