Avraham stitched the world to its root

במד' תנחומא מי שמדקדק על המצות שכרו מרובה כו' באברהם עקב אשר שמע כו' תורתי והלא תורה אחת היא רק הם דקדוקי מצות כו'.

In the Midrash Tanchuma: one who is meticulous about the mitzvos, his reward is great... regarding Avraham, "because he hearkened... [to] My Torah" (Bereishis 26:5) — but is there not only one Torah? Rather, these are the fine details of the mitzvos.

The Midrash asks why the verse says "Torahs" (plural) about Avraham and answers that it refers to his meticulous attention to the fine points of every mitzvah.

הענין הוא עפ"י מ"ש במד' על אאע"ה אחות לנו קטנה שאיחה את העולם.

The matter is based on what the Midrash says about Avraham Avinu on the verse "We have a little sister" (Shir HaShirim 8:8) — that he "stitched together" (icheh) the world.

The word "achos" (sister) is read as "icheh" (stitched): Avraham mended the torn fabric of the world.

והוא דביקות וחיבור הכל אל השורש וזה הי' הפרש של נח הצדיק לאברהם החסיד דאיתא חסיד העושה לפנים משורת הדין פי' הצדיק בודאי זהיר ומקיים כל המוטל עליו.

And this is the cleaving and connecting of everything to its root; and this was the difference between Noach the tzaddik and Avraham the chassid, for it is taught that a chassid is one who acts beyond the letter of the law (lifnim mi-shuras ha-din). The explanation: the tzaddik is certainly careful and fulfills all that is incumbent upon him —

Reconnecting all things to their Source distinguishes Avraham, the "chassid" who goes beyond obligation, from Noach, the "tzaddik" who merely fulfills his duty fully.

אבל החסיד מחפש בגנזי המלך ומדבק עצמו בפנימיות של המצוה ואינו עושה כדי לצאת ידי חובתו רק שבמצות ה' חפץ מאוד ומחפש אחר המצות תמיד ועי"ז מתגלה לו שורש המצוה.

— but the chassid searches in the treasuries of the King and cleaves to the inner dimension (penimiyus) of the mitzvah; he does not act merely to discharge his obligation, but rather "he greatly desires Hashem's mitzvos" (Tehillim 112:1) and constantly seeks out the mitzvos, and through this the root of the mitzvah is revealed to him.

The chassid digs into the inner essence of a mitzvah out of love and longing, not just to fulfill duty — and this is why the deeper root of each mitzvah opens up to him.

ולכן כתיב תורתי שכל מצוה יש לה שורש גבוה מאוד רק התלבשות אור המצוה הוא בגשמיות וכ' איחה את כל העולם כמי שמאחה את הקרע כי קודם חטא אדה"ר הי' הכל דבוק בשורש העליון רק כמ"ש עונותיכם הי' מבדילים.

Therefore it is written "My Torah," for every mitzvah has an exceedingly lofty root; only that the enclothing of the mitzvah's light is in physicality (gashmiyus). And it says he "stitched together the entire world," like one who mends a tear — for before the sin of Adam HaRishon everything was attached to the supernal root, only that, as it is written, "your iniquities have been separating" (Yeshayahu 59:2).

Each mitzvah has a sublime root merely clothed in physical form; sin tore the world from its Source, and Avraham's avodah re-stitched the tear, reconnecting creation to its root.

וע"י אברהם אבינו ע"ה התחיל להתגלות הפנימיות כנ"ל ובנח כתיב צדיק הי' בדורותיו אבל אברהם אע"ה הי' שורש לכל הדורות עד לעתיד.

And through Avraham Avinu the inner dimension (penimiyus) began to be revealed, as above; and regarding Noach it is written "he was a tzaddik in his generations," but Avraham Avinu was a root for all the generations until the future.

Avraham initiated the revelation of the inner light; unlike Noach, whose righteousness was limited to his own generations, Avraham became the root nourishing all future generations.

לכן אין קורין אבות אלא לשלשה ומזכירין אלקי אברהם יצחק ויעקב פי' שיש מהאבות ניצוץ לכל איש ישראל ובכח זה מקבל עליו עול מלכות שמים.

Therefore we call only three "Avos" (Patriarchs), and we mention "the God of Avraham, Yitzchak, and Yaakov" — meaning that there is a spark (nitzotz) from the Avos in every Jew, and by the power of this spark he accepts upon himself the yoke of the Kingdom of Heaven (ol malchus shomayim).

Only the three Avos are "fathers" because each Jew carries a spark of them, and this inherited spark is what empowers him to accept Hashem's sovereignty.

לכן ברכת אבות קודם שהוא פתח איך להתדבק בו ית' על ידי מעשה האבות:

Therefore the blessing of "Avos" comes first [in Shemoneh Esrei], for it is the opening of how to cleave to Hashem through the deeds of the Avos.

The Amidah begins with the blessing of the Avos because they are the gateway — their deeds show every Jew how to attach himself to Hashem.

Summary: The plural "Torahs" credited to Avraham points to his meticulous love for the inner details of every mitzvah. Unlike Noach the tzaddik, who merely fulfilled his duty, Avraham the chassid "searched in the King's treasuries," cleaving to the penimiyus of each mitzvah out of longing — and so he "stitched together" the world that sin had torn from its root, beginning the revelation of the inner light. Because Avraham became the root for all generations, every Jew carries a spark of the Avos that empowers him to accept the yoke of Heaven, which is why the Amidah opens with the blessing of the Avos.