Genesis 22:15-16

"And the angel of Jehovah called unto Abraham a second time out of heaven, and said, By myself I have sworn, saith Jehovah, because thou hast done this thing, and hast not withheld thy son, thine only son."

These verses are called "a supplement by a redactor" who decided the sparing of Isaac needed some greater reward than merely having his life spared.[22] Such an allegation rests solely upon the statement that "Jehovah ... called a second time." However, it is characteristic of the Bible that many such instances are given. For example, "The Word of Jehovah came the second time unto Jonah" (Jonah 3). No redactor ever touched this verse.

"Thine only son ..." How could God say that, when Abraham was also the father of Ishmael? The meaning, of course, is that Isaac was the son of promise, the only legitimate son born to his lawful wife.