Joel Marcus interprets the Testament of Abraham 11-12 to be identifying the Ancient of Days with Adam.
Joel Marcus, "Son of Man as Son of Adam," Revue Biblique 110, no. 1 (January 2003): 59n81
In T.Ab. 11-12, as in Daniel 7, *two* thrones are set up, one for the major figure (God = the Ancient of Days in Daniel, Adam in Testament of Abraham), who is described as brilliantly radiant and awe-inspiring, and the other for the secondary figure ("one like a son of man" in Daniel, Abel "the son of Adam" in Testament of Abraham), who is given or associated with the task of judging.