Whedon's Commentary on the Bible - Genesis 25:6
6. The concubines Hagar and Keturah . Sent them away Some have objected that Keturah’s sons, if born after Sarah’s death, were too young to be thus sent away . But Ishmael was only a lad of fifteen or seventeen years when sent away with his mother into the wilderness of Beer-sheba . Genesis 21:14. But the time of bestowing these gifts on the sons of his concubines, and sending them away, is uncertain . The different facts stated in Genesis 25:5-6 may have occurred at very different dates... read more
Whedon's Commentary on the Bible - Genesis 25:5
5. Gave all… unto Isaac This had been understood and settled long before . Genesis 24:36. read more