Ven. Huifeng or Jeff may know.
The source would depend on which is the older sutra between the Avatamsaka & the Original Karmas one. Also, chapters can be and were, stand-alone sutras, so the earliest appearance of these stages is not known by me.
As difference that is identical with unity does not block outward discernment, do not speak in adhesion to words. -- Ch'eng-kuan