Abraham’s family life is the stuff of Jew, Gentile, and Mormon legend. But, I’m not going to break into that territory much. It’s too complex and I don’t have the mental space for it now. But, who is Iscah? The name appears once in the Hebrew Bible, just after the genealogy of Abram:
And Abram and Nahor took them wives: the name of Abram’s wife was Sarai; and the name of Nahor’s wife, Milcah, the daughter of Haran, the father of Milcah, and the father of Iscah. [Gen. 11:29, KJV]
Just so you get the family tree here:
Terah (has three sons)
↓ ↓ ↓
Haran Abram Nahor
Haran (has two daughters)
Haran dies, Abram and Nahor get married. Who do they marry?
Abram marries Sarai. Nahor marries Milcah. Moreover, Milcah is identified as a daughter of Haran. So Nahor marries his niece. Right? There is a lot of water under this bridge, arguments about whether “daughter” means “daughter” or relative, etc. The text itself doesn’t give a clue there. Now, Sarai sort of appears out of the blue and Abram marries her.
Then there is this Iscah. She is Milcah’s sister apparently (observe that Hebrew meanings assigned to Milcah and Sarai are usually “queen” and “princess” respectively). Without violating the short format inherent in the blog world, I’ll just say that the traditional interpretation among Jews and Christians here was that Sarai and Iscah are the same person. For various reasons, over the last hundred years or so, people began to dispute the tradition, unlinking Iscah and Sarai. One reason is Genesis 20:12,
And yet indeed she [Sarai] is my sister; she is the daughter of my father, but not the daughter of my mother; and she became my wife.
Here Abram (now Abraham) identifies Sarai (now Sarah) as his half-sister. Now take your pick. Niece or sister. People have discussed the two positions a lot, but this is not my interest now.
Here is a passage from the Book of Abraham as it appears in it’s first printing, clearly edited by Joseph Smith himself:
Now the Lord God caused the famine to wax sore in the land of Ur, insomuch that Haran, my brother, died; but Terah, my father, yet lived in the land of Ur, of the Chaldees.
And it came to pass that I, Abraham, took Sarai to wife, and Nehor, my brother, took Milcah to wife, who were the daughters of Haran.
So Joseph Smith tells us in his translation/revelation called the Book of Abraham that Sarai is the daughter of Haran. This gives some weight to the Sarai = Iscah idea. Indeed, at the critical moment when Iscah makes her one and only appearance in the Hebrew Bible, she is replaced by Sarai.
This is interesting not just for following the Talmudic literature, Josephus, and other sources. Three earlier (c1835) Book of Abraham manuscripts reflect the Genesis text and so run counter to the 1842 first printing.
The first printing of the text was not altered (in the wording of the present passage) through the various successive printings of the Book of Abraham (another in 1842, followed by a fair number of 19th century editions, mostly as part of the Pearl of Great Price) until 1981. While there is no published source for the editing process for this edition, it seems clear that two things happened: 1) The Times and Seasons was consulted and 2) the four extant earlier manuscripts were consulted. The reading that was decided upon follows the Genesis text:
And it came to pass that I, Abraham, took Sarai to wife, and Nahor, my brother, took Milcah to wife, who was the daughter of Haran.[Abr. 2:2, current edition of the PoGP.]
Well, Iscah makes no appearance here, nor did she in the original text, but this new text does make way for the biblical reading. Personally, having studied the events surrounding the original publication rather carefully, I tend to go with the Times and Seasons reading as reflecting Joseph Smith’s final version of the text. Altering that by virtue(?) of manuscript versions in this case is not the same as appealing to some family of Greek New Testament MSS for a Bible translation. On the other hand, since the present text was canonized in 1981, it is the official version. Furthermore, it does not contradict the Times and Seasons text, it merely contains less “information.”
So there you are. The tiny Mormon story of Iscah. Who is she? Danged if I know.
 Nehor appears a couple times in the Book of Mormon as a person and place name. All Book of Abraham manuscripts follow the KJV spelling (Nahor) save one. I believe the Times and Seasons spelling was probably a typo.
 If you want to say this discussion is pointless because these people are not historical figures, well, go ahead. But it’s still an interesting textual weave. Anybody can appreciate that much. Personally, I’m rather in favor of a historical Abraham and so I don’t blanch a bit at Sarah, or Iscah, no matter how the stories evolved.