Comentário sobre Gênesis 25:2

.ותלד לו את זמרן, she raised them in his house, similar to the “five sons of Michal” who raised the children of her sister Merav who had died at an early age, and had born those to Adriel (compare Samuel II 21,8) Michal had no children of her own at all. Although Avraham had personally only sired Ishmael and Yitzchok, he had adopted these children as seems clear from Chronicles I 28, and 32.

ותלד לו את זמרן,”she bore Zimron for him.” Concerning Isaiah 29,22 אשר פדה אברהם, “who redeemed Avraham,” which according to our sages means that Avraham was freed from the burden of raising children, and which seems incompatible with the fact that he had to raise 6 children by Keturah, apart from the fact that most fathers enjoy having many children to raise, we must assume that what the author of that comment had in mind was that Avraham dd not have to experience the problems his grandson Yaakov faced when his son Joseph went missing, when his daughter Dinah was raped, and when various of his sons at different times behaved in a manner unacceptable to him.