The answer is: Keturah

Gen 25:1

Abraham's second wife, Keturah, adds a fascinating dimension to his story, illuminating many aspects of ancient life. After the death of Sarah, Abraham remained a man of great influence and wealth. Keturah's introduction after Sarah indicates that even in his later years, Abraham’s legacy was crucial. This wasn't just about keeping lineage continuing; it also reflects a custom of the time where prominent figures often married multiple wives to secure their family's wellbeing and prosperity.

Strikingly, Keturah bore Abraham six children: Zimran, Jokshan, Medan, Midian, Ishbak, and Shuah. The Midianites, descended from Abraham and Keturah, played significant roles throughout biblical history, notably in the story of Moses (Exodus 2:15) and even as traders who facilitated interactions between diverse cultures (Genesis 37:25).

Isaac, Abraham’s son with Sarah, represents the covenant line through which God's promise would unfold. However, Keturah's children remind us that God’s plans and blessings were wild and vast — spanning beyond one heir and one family tree. For trivia lovers, Keturah's name means "incense" in Hebrew, and her story shares echoes of various themes such as renewal, reconciliation, and the unexpected paths blessings might take.

So, in the life of Abraham, marriage to Keturah signifies continuity, divine abundance, and God’s compassion, reminding us that everyone has a story and a claim on divine promise.