The story of Abraham's half-truth occurs twice (Genesis 12:10-20; 20:1-18) and once with his son Isaac (Genesis 26:6-11). Destructive critics have noted this doublet (or triplet!) and assigned different sources to the three stories on the belief that it was one single event that was recounted over a period of time in various geographical areas and acquired enough differences to emerge as three different accounts.

However, close examination of the two principle accounts indicates that there are several major differences that challenge the premise that they are of one account. Notice the chart below that compares and contrasts the two accounts with Abraham:

In the sojourn to Egypt (Gen 12), Sarah was about 65 years old and was considered very beautiful. In the sojourn to Gerar (Gen 20), Sarah was about 90 years old. The Bible does not reveal why Abimelech desired Sarah's inclusion into his harem, and destructive critics do not find it credible that a Philistine king would romantically desire an old woman. However, by human standards, it is also difficult to understand Sarah's stunning beauty at age 65 and how she could be pregnant at age 90; thus, the possibility of Abimelech's attraction to her beauty cannot be ruled out. Furthermore, as Sarah was in the company of one of the richest and influential men in the region, Abimelech may have had a political motive.

Why did Abraham claim that Sarah was his sister and hide the fact that she was his wife? Sarah was indeed Abraham's half-sister (Gen 20:12), and both shared the same father Terah. In the first account in Egypt (Gen 12), Abraham had left Haran and had not been in Canaan long when the famine arose (Gen 12:1-9). In unfamiliar and perhaps hostile territory, the Bible reveals that Abraham asked Sarah to protect him by claiming to be his sister (Gen 12:13).

Was this an attempt to hide an incestuous relationship? This motive was unlikely as Abraham and Sarah were far from Ur and Haran where people may know of this relationship.

Was this an attempt to marry off Sarah so that Abraham would be profit from the dowry? This motive was unlikely as adultery was a serious crime in the Ancient Near East. Notwithstanding, it was also unlikely that Sarah would share this guilt or be party to this motive.

Was this a statement of declaring their marital status in the strongest possible terms? An ethnic group of people called Hurrians had a unique custom where adopting one's wife as one's sister created a double union, which was considered the strongest and most solemn relationship. The status guaranteed the woman special legal and social protections. Archeological findings indicated that Hurrians did reside in Haran and Ur, and Hittites and Semites did not practice this custom of giving one's wife the judicial status of a sister.

It is not likely that this was the motive, because the Hurrian custom was exercised either before or during the marriage ceremony and not later into one's marriage. It is also doubtful that other cultures would recognize the unique Hurrian custom, and a married spouse would have provided little protection to Abraham in a foreign land. Indeed, if Sarah's beauty were so compelling, Abraham would have increased his risk of physical danger in declaring that Sarah was his doubly unioned spouse.

Was this an attempt to have the ability to receive and deny potential suitors of Sarah? This was most likely the motive of Abraham's request. Marriage customs required that the suitor ask permission to court from the father of an unmarried daughter or the older brother of an unmarried sister. Abraham, positioned as the older brother, would be the recipient of courtesy and gifts as the suitor attempts to ingratiate himself. In negotiating for Sarah, Abraham was in position to set the price so high that the suitor would not be able to meet it; however, in both cases, the suitors were kings who likely had significant treasuries.

In regards to the account with Isaac and Rebekah who follows in his father's footsteps (Gen 26:1-11), destructive critics include this as another example of the Abraham wife-sister doublet because of their similarities in accounts, people involved, and covenants made thereafter (Gen 21:22-34; 26:26-31). The chart below that compares and contrasts the two accounts of Abraham (Gen 20:1-18) with Isaac (Gen 26:1-11):

Abimelech can be either the name of a person or royal title like Pharaoh. Its usage here refers to the royal title for Philistine kings. Isaac's account occurred some 90 years after Abraham's account and when Abraham was deceased, and it is unlikely that it is the same Abimelech in both accounts. Likewise, in the covenant accounts (Gen 21:22-34; 26:26-31), Phicol can be either the name of a person or a military title like general, and, because of the passage of time, it is not likely to be the same person.

Close examination of Abraham's wife-sister "doublet" reveals that these accounts are all separate and distinct events and not simply a retelling of a singular occurrence. Thus this is not evidence for the Documentary Hypothesis nor is this an example of the Ancient Near Eastern literary device of repetition or restatement.

Each wife-sister event serves a purpose in God's revelation.

The first incident with Pharaoh (Gen 12:10-20) occurred before Abram's name was changed to Abraham. Preceding the incident, God called to Abram to leave Haran and go to the Promised Land (Gen 12:1-9), and he responded with faith and obedience.

Yet, because of fear, Abram decided to go to Egypt and deceive the Egyptians with his half-truth and demonstrated a complete lack of faith in God's promised blessings; Abram did not need to leave Canaan and did not need to be deceptive. While this made Abram a wealthy man, he could not return to the Promised Land, and risked his wife's purity and promised blessings.

When Pharaoh discovered the truth, Abram received a royal rebuke and was expelled.

Did the end justify the means? No. Abram lied and brought dishonor to him and Sarah; he was a poor example of godliness. Pharaoh recognized that God was with Abram and allowed Abram to leave with his life and gifts, but Pharaoh expelled Abram with dishonor ("Now then, here is your wife, take her and go" [Gen 12:19]).

Would Abram still materially benefit had he been truthful? Yes, despite Abram's lack of faith and deception, God would have been faithful to His promises. This was the beginning revelation of God's unilateral and unconditional covenant with Abraham.

The second incident with Abimelech (Gen 20:1-18) occurred after the Abrahamic Covenant was made, after Abram's name was changed to Abraham, and after he was in the Promised Land.

Here again, Abraham decided to deceive the Philistines with his half-truth, and rationalizes his deceit in a most paradoxical way (Abraham said, "Because I thought, surely there is no fear of God in this place, and they will kill me because of my wife [Gen 20:11]). It was Abraham who lacked a fear of God.

Abraham's shame worsened as he attempted to excuse his deceit by claiming that his statement was true (Besides, she actually is my sister, the daughter of my father, but not the daughter of my mother, and she became my wife; [Gen 20:13]).

And Abraham debased himself to the lowest level when he claimed that God caused him to wander (and it came about, when God caused me to wander from my father's house, that I said to her, 'This is the kindness which you will show to me: everywhere we go, say of me, "He is my brother."' [Gen 20:13]). The Hebrew term for "wander" is not in a good sense. It is used when referring to straying animals, the staggering gait of a drunken man, or a lying heart.

The pagan king rebuked Abraham, yet the king still honored God by giving Abraham gifts and safe settlement on his land. But Abimelech held little regard for Abraham (To Sarah he said, "Behold, I have given your brother [Gen 20:16]). Later Abimelech would seek a covenant of peace (Gen 21:22-34).

The third incident, with Abraham's son Isaac (Gen 26:1-11), occurred after God renewed the Abrahamic Covenant in person. Like his father, Isaac acted dishonorably. While he didn't leave the Promised Land, Isaac chose to be deceptive and was rebuked by a pagan king.

These three wife – sister incidents revealed God's determination to fulfill His covenant promises despite the faithless human efforts of the patriarchs to save themselves. In each case, while Abraham and Isaac both thought they could control the situation, they instead placed Sarah and Rebekah at risk of defilement with another man; only God could safeguard their purity and chastity for the blessings that would come. The extent of how faithless the Patriarchs were cannot be appraised in the absence of their historical context; each wife – sister incident followed significant historical covenantal events with God. And in the end, despite their show of faithless behavior, both Abraham and Isaac were noted for their faith in God in Hebrews 11:8-19.