What does the Bible say about Abraham's lineage and heirs?

In Genesis 25, we see that Abraham took a wife named Keturah and had several children. However, when it came time to bestow his inheritance, Abraham gave everything he had to Isaac, illustrating Isaac's significance as the promised son and heir. This act highlights a vital truth in Scripture about God's plan for Isaac as the bearer of the covenant, representing God's choice and sovereign will in the lineage that would lead to Christ. The other children, despite being given gifts, were sent away, demonstrating the unique status of Isaac as the heir. This reflects the larger narrative of God's electing grace throughout the Bible, where particular individuals are chosen for divine purposes.