唯識二十論述記 2.194

2.194

述曰：下破薩婆多等，此等執境及心、心所皆念念滅，名剎那論。「有此覺時」釋頌第二句，牒彼所計。

The commentary says: Below, the Sarvāstivāda and others are refuted. These schools hold that objects, mind, and caittas all cease moment by moment, and are called momentariness theorists. 'When this awareness exists' explains the second line of the verse, restating their position.