Hashem announces to Avrohom that Sarah Imeinu will have a child he will be considered his only eternal child. Hashem explains that only this child (from Sara Imeinu) will eventually get Eretz Yisroel. Avrohom argues with Hashem and says: Hashem let it suffice that I have Yishmael and let him live on as my eternal heir (17: 15-18).this entire episode leaves us baffled with the question what is going on? Hashem tells Avraham seemingly the best news and instead of rejoicing Avraham seems to object.
Hashem doesn’t seem to answer Avraham’s question rather only reasserts His previous statement: Sarah will give birth to Yitzchok and he will be your prodigy. Hashem also adds that Yishmael as well will become a great nation; that Yishmael would be twelve tribes.
The Ohr-HaChaim in the beginning of the parsha comments that the Nevuah/ prophecy of Avrohom was different than that of all other Neviem/prophets. Usually Hashem would first show to the neviyim a vague Nevuah and only afterwards explain its specifics whereas Avrohom received his Nevuah in a regular clear cut way.
The Ohr-HaChaim suggests two possible answers. The first answer he gives is that Avrohom was indeed different from all other prophets. While all others started with knowledge of Hashem, His Torah, and His mitzvos, Avrohom didn’t. Avrohom worked on his very own to find and understand Hashem. Avrohom therefore recognized Hashem much clearer than all others. Hence, Avrohom merited having Devine revelation in verbal form, thus being more vivid.
Avrohom Aveinu’s adherence to Torah and Mitzvos was based on his understanding of Hashem and His Will. Avrohom’s every act was based on his own understanding of Hashems Will.
Avrohom had finally come to terms with the fact that Sarah Imeinu wasn’t going to have children. He therefore understood that he would have to have a choild from a different union. Avrohom’s willingness to have a relationship with Hagar was only in order to have a child. Avrohom was willing to live with Hagar for the sake of having Am-Yisroel. Hashem after all this tells Avrohom: no. Hashem tells Avrohom that Sarah will give birth to a son Yitzchok, and that through Yitzchok will his lineage stem. Avrohom Avinu is baffled, he is all of a sudden void of understanding, and he was possibly dubious to his union with Hagar.
Hashem doesn’t merely reassert that through Yitzchok will Avrohom descend, but he reassures him that Yishmael is of great importance as well, that he too will become a great nation. Perhaps Hashem telling Avrohom that Yishmael Will become twelve tribes, was for the same purpose. Hashem was telling Avrohom that his understanding that Yishmael would be the Twelve Tribes that would comprise Klal-Yisroel was because Yishmael as well would be twelve tribes.
Avrohom Avinu isn’t arguing with Hashem, rather he is expressing his desire to understand Hashem. Due to Avrohom’s meticulous care to Hashem’s will he is concerned lest he erred.
We live with the Torah as a given, but that doesn’t mean that we need not understand it to the utmost. Understanding and being concerned that we are adhering to Gods will, must always concern us.
Good Shabbos, Rabbi Y.Dov Krakowski