In contrast with Sravakayana, Mahayana asserts (AFAIK) that the place where the Buddha really attains his annuttara samsaysambodhi is not under the Bodhi tree on Jambudvipa, but in Akanistha. I have a few questions regarding this:
1. Anyone knows the earliest sutra that mentions this? I know the Lankavatara mentions this, but not sure if it is the earliest.
2. Frequently from Tantric Buddhists, we hear that this Akanistha is not the Akanistha in the Form Realm, but rather a pure land beyond the three worlds. From what I can gather, this seems to be a later interpolation, and that the earlier Mahayana sutras does mean the same place where non-returners attain Arhatship. Am I right in this? If so, anyone knows which tantra or sutra is the earliest that asserts this pureland Akanistha?
Thanks in advance.
Guhyagarbha Tantra. Here Akanista isn't a place but a meditation level characterized by the appearance of the five colored wisdom lights originating in the center of the heart