Genesis 20:12

“And yet indeed [she is] my sister, etc.] In the same sense as Lot was his brother; for she was sister to Lot, and both were the children of Haran, the brother of Abraham: she [is] the daughter of my father, but not the daughter of my mother; she was the daughter of his father, being his granddaughter, grandchildren are sometimes called children, but not the daughter or granddaughter of Abraham’s mother; Terah having had two wives, by the one he had Haran, the father of Sarah, and by the other Abraham. According to the Arabic writers f1203, Abraham and Sarah were the immediate children of Terah, but by two mothers: “the mother of Abraham (they say) died, whose name was Juna, and Terah married…”

“yet indeed she is my sister--(See on Gen 11:31). What a poor defense Abraham made. The statement absolved him from the charge of direct and absolute falsehood, but he had told a moral untruth because there was an intention to deceive (compare Gen 12:11-13). "Honesty is always the best policy." Abraham's life would have been as well protected without the fraud as with it: and what shame to himself, what distrust to God, what dishonor to religion might have been prevented! "Let us speak truth every man to his neighbor" [Zac 8:16; Eph 4:25]. Next: Genesis Chapter 21”

“- Abraham in Gerar 2. אבימלך .2 'ǎbı̂ymelek, Abimelekh, “father of the king.” 7. נביא nābı̂y' “prophet,” he who speaks by God, of God, and to God, who declares to people not merely things future, but also things past and present, that are not obvious to the sense or the reason; related: “flow, go forth.” 13. התעוּ hı̂t‛û is plural in punctuation, agreeing grammatically with אלהים 'ĕlohı̂ym. ו(w), however, may be regarded as the third radical, and the verb may thus really be singular. 16. נכהת nokachat an unusual form, either for נכחת nokaḥat the second person singular feminine perfect or נכחה nokeḥâh the third person singular feminine perfect, from a verb signifying in hiphil, “make…”