The first blessing of the Shemoneh Esreiis called Avot (Forefathers), because it begins by mentioning Avraham, Yitzchak and Yaakov. In contrast, this blessing concludes with the phrase “Shield of Avraham” instead of saying “Shield of the Avot”, thereby giving Avraham greater status than both Yitzchak and Yaakov.
You Will Be a Blessing
Our Sages explain that G-d hinted to Avraham when He said, “And you will be a blessing, (Bereshet 12:2)” that the first blessing of the Shemoneh Esrei would be represented by him. Thus, in order to express that Avraham is the main character of the first blessing, only his name is mentioned at its end.
Rabbi Levi Yitzchak of Berditchev explains the deeper meaning behind this discussion. There are three attributes through which G-d governs all creation: the attribute of G-d’s love and kindness; the attribute of judgment ― through which G-d punishes ― and the attribute of G-d’s mercy.
When G-d relates to His creations with love, then all the worlds are full with an abundance of good. If, however, He relates to the world with severity, judging the world for its misdeeds, the result can be the opposite. When G-d relates to the world through the attribute of mercy, the world also experiences abundant good. This is because the ultimate purpose of this attribute is also love. G-d therefore feels great pride and glory, so to speak, when He sees His creations through this attribute, and is therefore motivated to give them good despite their flaws.
Regarding G-d’s attribute of strict judgment, even though on the surface it appears to be the opposite expression of love since it is through this attribute that He punishes the world, nevertheless the ultimate purpose of G-d’s judgment is to facilitate the giving of perfect good afterwards. And so, in truth, the root and essence of the attribute of judgment is also love, even though it is concealed.
It is well-known that Avraham corresponds to the attribute of love and kindness, Yitzchak to severity and judgment and Yaakov to mercy. Accordingly, we can gain new insight as to why all three of the Avot are mentioned in this blessing. They represent the three general ways that G-d interacts with His world.
And now we can also understand why we conclude the blessing only with Avraham. Since he represents the attribute of love and kindness — the foundation of the creation and the inner purpose of all of G-d’s attributes — the blessing concludes only with Avraham’s name. This conveys that it is G-d’s love, which is represented by Avraham, that encompasses all — even the attributes of judgment and mercy which are represented by Yitzchak and Yaakov respectively.