成唯識論述記 2.472

2.472

述曰：此即最初、總非無實。薩婆多等實有無為，此中皆破。然不相應即色、心等，故初遮中皆言不異，此諸無為非即色等，不可言不異，但可言離色等實有定無。大乘真如望有為法，非即非離，不異不一，既殊彼計，故破無失。

The Commentary states: This is the very first: a general denial of their having real existence. The Sarvāstivādins and others hold that unconditioned dharmas are real; all are refuted here. However, unassociated formations are precisely form, mind, etc., so in the earlier refutations, all stated they are "not different". These unconditioned dharmas are not identical to form and so forth, so one cannot say they are "not different"; one can only say that being real entities apart from form and so forth is definitively non-existent. In the Mahāyāna, tathatā, in relation to conditioned dharmas, is neither identical nor separate, neither different nor identical; since it differs from their tenet, our refutation is without fault.