Summary: A silly change in Divine appellation, by Samaritan scribes, at the start of Vaera.
Post: The parasha leads off with:
One could ask a straightforward question on pasuk 2. If the statement is "I am YKVK", why should the one be speaking be Elokim?!
The answer, to me, is equally straightforward. This is surely a transition text. He is telling Moshe that he, the same God who spoke to him before is YKVK, though He did not make that name known to the avos. (Yes, there are other ways of understanding this pasuk.) As such, it makes sense to lead with Elokim speaking.
However, the Samaritans have a much more elegant solution. They simply change Elokim to YKVK:
(Yes, it could be to match the YKVK speaking in the previous pasuk, but my intuition is that it is to harmonize within the pasuk itself.)
I would compare this with the ridiculous emendation they offer for parashat Shelach. There the Torah lists the names of the spies who will be sent to scout out the land. Among those is Hoshea bin Nun. The Torah informs us, after this, that Moshe called, to Hoshea bin Nun, Yehoshua.
But if Moshe called him this, shouldn't we refer to him as this? And we do want a smooth, harmonious text. And so, they emend as follows:
Thus, it is Yehoshua bin Nun who is sent. And we are "helpfully" informed that Moshe called Yehoshua bin Nun Yehoshua!