The episode of Akeidat Yitzchak perplexes even the greatest of minds.
Why would God request Avraham to sacrifice his beloved son, the one from which He promised would spring forth the great nation of the covenant?
The last few pasukim at the end of the previous parsha, Lech Lecha, where we are informed about the circumcision of Avraham and Yishmael may provide some insight. Oddly, the details are divided into three separate verses when all the information could have concisely fit into one verse. Perhaps each one is meant to highlight one particular aspect of their circumcision.
In the first accounting, it says:
וַיִּקַּ֨ח אַבְרָהָ֜ם אֶת־יִשְׁמָעֵ֣אל בְּנ֗וֹ וְאֵ֨ת כָּל־יְלִידֵ֤י בֵיתוֹ֙ וְאֵת֙ כָּל־מִקְנַ֣ת כַּסְפּ֔וֹ כָּל־זָכָ֕ר בְּאַנְשֵׁ֖י בֵּ֣ית אַבְרָהָ֑ם וַיָּ֜מָל אֶת־בְּשַׂ֣ר עָרְלָתָ֗ם בְּעֶ֨צֶם֙ הַיּ֣וֹם הַזֶּ֔ה כַּֽאֲשֶׁ֛ר דִּבֶּ֥ר אִתּ֖וֹ אֱלֹהִֽים
And Abraham took Ishmael his son and all those born in his house and all those purchased with his money, every male of the people of Abraham’s household, and he circumcised the flesh of their foreskin on that very day, as God had spoken with him
The word “vayikach”, to take, indicates that it was Avraham who willingly got the process started by taking Yishmael to be circumcised.
In the second accounting, it says:
וְיִשְׁמָעֵ֣אל בְּנ֔וֹ בֶּן־שְׁל֥שׁ עֶשְׂרֵ֖ה שָׁנָ֑ה בְּהִ֨מֹּל֔וֹ אֵ֖ת בְּשַׂ֥ר עָרְלָתֽוֹ:
And Ishmael his son was thirteen years old, when he was circumcised of the flesh of his foreskin.
Here we are informed that Yishmael was thirteen which according to Jewish tradition is the age a boy transitions into a man thus becoming responsible and accountable for his behavior. Yishmael had the right and the ability to refuse to do the brit, but instead, he went along with it. Therefore the verse highlights this point to give him praise.
In the third accounting, it says:
בְּעֶ֨צֶם֙ הַיּ֣וֹם הַזֶּ֔ה נִמּ֖וֹל אַבְרָהָ֑ם וְיִשְׁמָעֵ֖אל בְּנֽוֹ:
On that very day, Abraham was circumcised, and [so was] Ishmael his son.
We already know that Yishmael is Avraham’s son. I believe the repeated emphasis here is to indicate that this difficult task which they underwent together forged a strong father/son bond that was unique and meaningful.
In the previous parsha, God reiterates the covenant he made with Avraham. At that point, Avraham makes a plea for Yishmael’s future, whereby God reassures him that Yishmael will have a promising future but will not be the one to fulfill the covenant, rather it will be Yitchak who will issue forth from Sarah. Shortly after, it describes the sacrifice of circumcision that Avraham and Yishmael performed together connecting them in purpose and devotion to God. It would seem only fair that Yishmael should merit the covenant. Although Yitzchak too was circumcised, he was merely eight days old and had no say or awareness of the event. While it is true that Yitzchak was righteous his entire life, if he had never experienced anything tantamount to the ordeal that Yishmael went through together with Avraham he would not only lack in the bond with his father but also experientially in his willingness to sacrifice for God.
The episode of the Akeida gave Avraham and Yitzchak the opportunity to experience a sacrifice of their own together for God to create a bond worthy of such merit. Without the Akeida which displayed their connected willingness to sacrifice everything for God the question would arise as to why should Yitzchak merit the covenant. The fact that Avraham and Yitzchak went through this together shows not only the connection forged between Avraham, Yitzchak, and God but also displays the spiritual fortitude of Yitchak deeming him worthy of the covenant.