大方廣佛華嚴經隨疏演義鈔 63.90

63.90

疏「略不明老」者，上依論觀生老病死。生苦在初，病可卒加、通於老少，故經明之。今生死言，即兼死苦。老言不顯，故云略無，亦合有也。

Regarding the commentary's: "Omission of not explaining old age": Above, one contemplated birth, old age, sickness, and death based on the Treatise. The suffering of birth comes first; sickness can suddenly strike and applies equally to the old and the young, and so the sūtra explains it. Here, the expression "birth and death" combines the suffering of death. The word "old age" is not evident, so it is said to be omitted; it should also be present.