Mistakes of Moses Expanded Universe: Genesis 25

In this installment Abraham dies (or does he?) but not before knocking up a concubine to the tune of six more sons, Rebekah needs divine intervention to get pregnant and immediately regrets that decision, and Yahweh hates a guy before he's even born.

Mistakes of Moses Expanded Universe: Genesis 20 & 21

In this installment we get to experience a bit of déjà vu when Abraham once again becomes worried about his super-hot nineteen-year-old ninety-year-old wife, we find another big fat anachronism, we see once again how possession (of a woman) is nine-tenths of the law unless Elohim threatens to smite you, and we get to see just how much of a physically underdeveloped little man-child Ishmael must've been at seventeen.

Genesis 20:1-17

Abraham lives as a temporary resident in Gerar, a Philistine city that current archeology tells us wouldn’t be inhabited until 1200 BC at the earliest and not as anything more than a small village until about 800 BC, putting it hundreds of years after the time when the Patriarchs lived or when Moses supposedly wrote this account (Finkelstein and Silberman, The Bible Unearthed, pp. 37-38). While there, not-so-honest Abe has his ninety-year-old sister/wife once again trick the locals into thinking that they aren’t married. Exactly as happened in chapter 12 during the first of the three "Dude, she's just my sister" patriarchal narratives, the ruler sees the nubile nonagenarian and takes her as a wife. In chapter 12 it’s Yahweh that threatens Egypt. Here in Gerar it’s Elohim. Later in 26:6-11 when Isaac pulls the same thing one more time on Abimelech, no specific deity will be named directly.