Epiphanius in his
Panarion calls the Essenes
Samaritans.
There is a great deal of evidence discussed
here, that Samaritans/Samarians were well-settled in the Fayum of Egypt c. 250 BC. Samareitai might have referred to an ethnic 'Old Jewish' group. To outsiders, the long indigenous Samarians (who were quasi-Jewish, mixing w/ locals and 'orthodox' Jews) might have been conflated with the true
Samaritans of Samaria, c. 100 AD.
Re: Egypt (from Reinhard Pummer's "The SAMARITANS IN EGYPT" in
Etudes Semitques et Samaritanes offered to Jean Margain, Series: Histoire du Texte Biblique 4 – pp.213-23)
In the Fayyum, a place was called 'Samareia', most likely because the original settlers came from that region. It is not known when they settled there. The village is first mentioned in the papyri of the late 3rd cent. B.C.E. [21]. The settlers could have been Samarians or (Proto-) Samaritans. However, most scholars assume that the inhabitants were Samaritans[22]. Yet, gradually the latter must have intermarried with Jews and the settlement lost its original character[23]. Eventually, Samareitai in Egypt came to mean 'inhabitants of (the village of) Samareia'[24].
From Origen's familiarity, and other Samaritan connections to Egypt,it's possible that 'Dositheus the Samaritan' may not have actually been from (or active in) Samaria itself. That the 'Samaritans' were also seen as
Zadokites in Egypt also makes sense: they were a nebulously-defined ethnic.
Any other recommended sources on the 'Samaritans of Egypt'?
As an important side-note for my own work, W. M. Flinders Petrie's
Personal religion in Egypt before Christianity [1909]
p.79 follows and builds upon Moritz Friedländer's
Therapeut-Essene thesis.
"of course, we have but a meagre statement, but as these ideas were familiar to Philon and Josephus they would be likely to allude to them had they been as prominent to the Therapeutae and Essenes as they were to their contemporaries. The explanation of these silences may well be that the writings so often mentioned as being treated with the greatest respect, were earlier than the rise of the ideas of the Wisdom and Logos. This is quite likely ; Wisdom, though often named as a quality, is not personified in Ecclesiastes, about 250 B.C. ; it is personified in Sirach, Ecclesiasticus, about 180 B.C., and in the book of Wisdom, perhaps 100 B.C. Hence the scriptures of the ascetics may be dated from before 200 B.C., as they did not refer to it. As we have seen that the ascetic community was already started at the back of the Fayum by 340 B.C., and that all their dogmas stated in later times were already familiar then in the Hermetic works, these points all agree well together. The Hermetic works are in fact the scriptures of the Ascetics."
This is the earliest suggestion (i.e. scholarly reference) that I have been able to locate, that Therapeutae wrote the
Corpus Hermeticum. (I do NOT agree with Petrie's early dating of the
Hermetica, however!)