Explanation:

Sarvastivadin is one of the earliest sects of Buddhism which attained prominence in the region of Mathura and in Kashmir. It held to the existence of all dharmas in the past, present and future, the 'three times'.

It considers everything empirical to be impermanent and maintains that the dharma factors are eternally existing realities. The dharmas are thought to function momentarily, producing the empirical phenomena of the world, which is illusory but to exist outside the empirical world.