Refining Middos Through Torah
במדרש ונשבעת חי ה' כו' כבר כ' במ"א והענין דכתיב ובשמו תשבע לשון נפעל וכ"כ ונשבעת ולא ותשבע רק זה העדות כשכל (אדם) [*האדם] מתפעל בזכרון שמו ית' אז הוא שבועת אמת
In the Midrash on the verse "And you shall swear, 'As Hashem lives'" (Yirmiyahu 4:2), I have already written elsewhere on this matter. For it is written "and by His Name you shall swear" (Devarim 10:20) in the passive form, and likewise "and you shall swear" rather than "and you swear" — for this is the testimony, that when a person is wholly stirred and aroused through remembering His blessed Name, then his oath is an oath of truth.
An oath is called "true" only when one is genuinely moved by remembering Hashem's Name. The passive grammar hints that the person is acted upon — stirred — rather than merely speaking words.
וצריכין מקודם לתקן המדות עד שזוכין לזה כמ"ש במקום אחר שיש באדם דצח"ם אמת משפט וצדקה כו' אח"כ זוכין לבחי' מדבר והוא הגמר להיות נידבר ובטל אליו ית' ולדברי תורה שכל התורה שמותיו של הקב"ה
But first one must refine and rectify the middos until he merits this, as I have written elsewhere that within a person there are the levels of inanimate, plant, animal, and speaking being (domem, tzomei'ach, chai, medaber) corresponding to truth, justice, and tzedakah; afterward one merits the level of "speaker," and this is the culmination — to become one who is spoken through and nullified to Him, blessed is He, and to the words of the Torah, for the entire Torah is comprised of the Names of the Holy One, Blessed is He.
Before reaching that level a person must first refine his character traits, climbing through the levels of creation until he attains the rank of "speaker," where he becomes a vessel nullified to Hashem and to His Torah, which is itself made of His Names.
וז"ש התקן עצמך ללמוד תורה
This is the meaning of "Prepare yourself to learn Torah" (Avos 2:14).
This explains the Mishnah's teaching that one must first prepare himself in order to learn Torah.
כשהאדם מתוקן
When a person is properly rectified,
The preparation it speaks of is when a person has properly rectified himself.
כל הדברים שלומד מביאין לידי מעשה כמ"ש מגדל עוז שם ה' כו' והוא התורה כו'
all the matters that he learns bring him to actual deed, as it is written "a tower of strength is the Name of Hashem; the tzaddik runs into it and is elevated" (Mishlei 18:10) — and this refers to the Torah.
Once a person is rectified, his learning naturally leads to action, for the Torah is a fortress through which the tzaddik rises, drawing his study down into deed.
ואמת כמ"ש (אשר יוצא) [*ככל היוצא] מפיו יעשה וכשאדם זוכה מתקיים בעוה"ז או לעתיד
And this is emes, as it is written "according to all that comes out of his mouth he shall do" (Bamidbar 30:3); and when a person merits, it is fulfilled in this world or in the World to Come.
Such learning carries the quality of emes — what he declares is fulfilled, whether in this world or in the World to Come.
ומרע"ה הנהיג את דורו בכל המדריגות עד שעתה עמדו בבחי' ובשמו תשבע שהוא סוף כל המדריגות בפסוק הנ"ל:
And Moshe Rabbeinu led his generation through all the levels, until now they stood at the level of "and by His Name you shall swear," which is the end of all the levels alluded to in the aforementioned verse.
Moshe Rabbeinu guided Bnei Yisrael up through every level until they reached the highest rung, that of swearing by Hashem's Name.
Summary: The Sfas Emes explains that a true oath is not merely a verbal act but the result of a person being wholly stirred by remembering Hashem's Name — which is why the verses use the passive form. To reach this level one must first rectify his middos, ascending through the levels of creation until attaining the rank of "speaker," where he becomes nullified to Hashem and to the Torah, which is comprised entirely of His Names. This is the meaning of "Prepare yourself to learn Torah": once a person is properly rectified, his learning flows into action, carrying the power of emes so that what he declares is fulfilled in this world or the next. Moshe Rabbeinu led his generation through all these levels until they stood at the final rung — swearing by Hashem's Name.