What does Genesis 25:1 mean?

Bible interpreters disagree about when Abraham married Keturah, his "other wife." Does the text mention this marriage here because it came after Sarah's death, as has been traditionally understood? This is possible, but ancient literature was not written in the same chronological sense as modern history. The other, more likely possibility is that Abraham married Keturah before Sarah died. Given that Abraham had six children with Keturah, it seems more likely that theirs was an ongoing relationship, not one which did not even start until Abraham was nearly 140 years old (Genesis 23:1–2; 17:17).

The text is not clear as to which of these two options is the truth. In 1 Chronicles 1:32, Keturah is described as Abraham's concubine. In any case, the following verses will reveal that Abraham had six sons with Keturah. None of them were included in the covenant promises given by God to Abraham and then Isaac.