成唯識論演祕 5.433

5.433

由時促故，隨緣一蘊，名一一也。故後起等，得有邊名。餘准此知。

Because the duration is brief, apprehending any single aggregate is termed 'each one'. Therefore, subsequent arisings and so forth receive the designation 'finite'. The rest should be understood by analogy to this.