Then again Abraham took a wife, and her name was Keturah.
All Commentaries on Genesis 25:1 Go To Genesis 25
Augustine of Hippo
AD 430
As for those who prefer to read no symbolic meanings into such facts, they still have no ground of complaint against Abraham. For, in the literal sense, there may be meant to be here an argument against those heretics who are opposed to second marriages, since the example of the very father of many nations proves that there is no sin in a second marriage that is made after one’s wife is dead.