Rabbi Isaac Luria wrote that the acrostic of certain biblical verses spells Elul, indicating that this month is a time of divine favor for repentance from sins committed throughout the year and even for unintentional transgressions, and other interpreters of textual signs similarly identified acrostics of Elul in other verses.
מֵרֹאשׁ חֹדֶשׁ אֱלוּל עַד אַחַר יוֹם הַכִּפּוּרִים, הֵמָּה יְמֵי רָצוֹן. וְאַף כִּי בְּכָל הַשָּׁנָה הַקָּדוֹשׁ בָּרוּךְ הוּא מְקַבֵּל תְּשׁוּבָה מִן הַשָּׁבִים אֵלָיו בְּלֵב שָׁלֵם, מִכָּל מָקוֹם יָמִים אֵלּוּ מֻבְחָרִים יוֹתֵר וּמְזֻמָּנִים לִתְשׁוּבָה, לִהְיֹתָם יְמֵי רַחֲמִים וִימֵי רָצוֹן, כִּי בְּרֹאשׁ חֹדֶשׁ אֱלוּל, עָלָה משֶׁה אֶל הַר סִינַי לְקַבֵּל לוּחוֹת שְׁנִיּיּם, וְנִשְׁתֵּהָה שָׁם אַרְבָּעִים יוֹם, וְיָרַד בַּעֲשָֹרָה בְּתִשְׁרִי, שֶׁהָיָה אָז גְּמַר כַּפָּרָה. וּמִן אָז הֻקְדְּשׁוּ יָמִים אֵלּוּ לִימֵי רָצוֹן, וְיוֹם עֲשִׂירִי בְּתִֹשְרִי לְיוֹם הַכִּפּוּרִים. וּמִנְהָג בְּרֹב הַמְּקוֹמוֹת לְהִתְעַנּוֹת בְּעֶרֶב רֹאשׁ חֹדֶשׁ אֱלוּל וְלַעֲשׂוֹת סֵדֶר יוֹם כִּפּוּר קָטָן, כְּדֵי שֶׁיָּכִינוּ לִבָּם לִתְשׁוּבָה. וְאִם חָל רֹאשׁ חֹדֶשׁ בַּשַׁבָּת, מַקְדִּימִין לְיוֹם חֲמִישִּׁי שֶׁלְּפָנָיו. הָרַב אֲדוֹנֵנוּ רַבִּי יִצְחָק לוּרְיָא זִכְרוֹנוֹ לִבְרָכָה כָּתַב, וַאֲשֶׁר לֹא צָדָה וְהָאֱלֹהִים אִנָּה לְיָדוֹ וְשַׂמְתִּי לְךָ, רָאשֵׁי תֵּבוֹת אֱלוּל, לוֹמַר כִּי חֹדֶשׁ זֶה, הוּא עֵת רָצוֹן לְקַבֵּל תְּשׁוּבָה עַל הַחֲטָאִים שֶׁעָשָׂה בְּכָל הַשָּׁנָה. וְגַם רֶמֶז שֶׁגַּם עַל הַשְּׁגָגוֹת צָרִיךְ לַעֲשׂוֹת תְּשׁוּבָה בַּחֹדֶשׁ הַזֶּה. עוֹד אָמְרוּ דּוֹרְשֵׁי רְשׁוּמוֹת, וּמָל ה' אֱלֹהֶיךָ אֶת לְבָבְךָ וְאֶת לְבַב זַרְעֶךָ, רָאשֵׁי תֵּבוֹת אֱלוּל. וְכֵן אֲנִי לְדוֹדִי וְדוֹדִי לִי, רָאשֵׁי תֵּבוֹת אֱלוּל. וְכֵן אִישׁ לְרֵעֵהוּ וּמַתָּנוֹת לָאֶבְיוֹנִים רָאשֵׁי תֵּבוֹת אֱלוּל. רֶמֶז לִשְׁלֹשָׁה דְּבָרִים, שֶׁהֵם, תְּשׁוּבָה, תְּפִלָּה וּצְדָקָה, שֶׁצְרִיכִין לְהִזְדָּרֵז בָּהֶם בְּחֹדֶשׁ זֶה. וּמָל ה' וְגוֹ' רוֹמֵז לִתְשׁוּבָה. אֲנִי לְדוֹדִי וְגוֹ' רוֹמֵז לִתְפִלָּה, שֶׁהִיא רִנַּת דּוֹדִים. אִישׁ לְרֵעֵהוּ וּמַתָּנוֹת לָאֶבְיוֹנִים, רוֹמֵז לִצְדָקָה.
[The days] from Rosh Chodesh Elul until after Yom Kippur, are days of Divine favor [and acceptance.] Even though throughout the entire year the Holy One, blessed is He, accepts the repentance of those who return to Him wholeheartedly, nevertheless, these days are unexcelled and most suitable for repentance, because they are days of mercy and favor. On Rosh Chodesh Elul, Moshe went up Mount Sinai to receive the Second Tablets; he remained there for forty days, and came down on the tenth day of Tishrei when the atonement was completed. From then on these days have been designated as days of Divine favor [and acceptance,] and the tenth day of Tishrei as Yom Kippur [Day of Atonement]. In most communities it is the custom to fast on the day before Rosh Chodesh Elul and to recite the prayers of Yom Kippur Katan [minor Yom Kippur], in order to be spiritually prepared for repentance. If Rosh Chodesh occurs on Shabbos, Yom Kippur Katan is held on the preceding Thursday. The Ari (Rabbi Yitzchak Luria), of blessed memory, wrote, "If he did not lie in ambush but Hashem made it happen, then I will provide …" (Exodus 21:13) The initials of the words [ina le'yado vesamti lecha] form the acronym Elul, to indicate that this month is a favorable time for repentance to be accepted for the sins committed during the entire year. It also alludes to the fact that sins done inadvertently also require repentance during this month. The interpreters of allusions also commented: It is written (Deuteronomy 30:6) "And Hashem your God will circumcise your heart and the heart of your children;" the initials of the words [es levavecho ve'es levav] form the acronym Elul. Also, the initials of Ani ledodi vedodi li, ["I am my Beloved's and my Beloved is mine,"] [Song of Songs 6:3] form the acronym Elul. Also, the initials of Ish lerei'eihu umatanos la'evyonim ["One to another and gifts to the poor"] (Esther 9:22) form the acronym Elul. These acronyms are an allusion to three things: Repentance, Prayer and Charity which must be practiced zealously during this month. "Hashem will circumcise etc." alludes to repentance, "I am my Beloved's etc." alludes to prayer, for prayer is the song of love. "One to another and gifts to the poor," alludes to charity.
