How could I rejoice? When enemies fall.

בתר דשקלינהו למזייה לבשינהו למאניה אמר ליה סק ורכב אמר ליה לא יכילנא דכחישא חילאי מימי תעניתא גחין וסליק כי סליק בעט ביה אמר ליה לא כתיב לכו (משלי כד, יז) בנפל אויבך אל תשמח אמר ליה הני מילי בישראל אבל בדידכו כתיב (דברים לג, כט) ואתה על במותימו תדרוך (אסתר ו, יא)

Megillah 16a:10

After Haman trimmed his hair, Haman dressed Mordecai in the royal garments. Haman then said to him: Mount the horse and ride. Mordecai said to him: I am unable, as my strength has waned from the days of fasting that I observed. Haman then stooped down before him and Mordecai ascended on him. As he was ascending the horse, Mordecai gave Haman a kick. Haman said to him: Is it not written for you: “Do not rejoice when your enemy falls” (Proverbs 24:17)? Mordecai said to him: This statement applies only to Jews, but with regard to you it is written: “And you shall tread upon their high places” (Deuteronomy 33:29).

סנהדרין ל״ט ב:ג׳-ה׳

א"ר אחא בר חנינא (משלי יא, י) באבוד רשעים רנה באבוד אחאב בן עמרי רנה ומי חדי קודשא בריך הוא במפלתן של רשעים הכתיב (דברי הימים ב כ, כא) בצאת לפני החלוץ ואומרים הודו לה' כי לעולם חסדו ואמר רבי יונתן מפני מה לא נאמר בהודאה זו כי טוב לפי שאין הקדוש ברוך הוא שמח במפלתן של רשעים דאמר ר' שמואל בר נחמן אמר ר' יונתן מאי דכתיב (שמות יד, כ) ולא קרב זה אל זה כל הלילה באותה שעה בקשו מלאכי השרת לומר שירה לפני הקב"ה אמר להן הקב"ה מעשה ידי טובעין בים ואתם אומרים שירה לפני

Sanhedrin 39b:3-5

Rav Acha bar Chanina said: “When the wicked perish, there is song;” [thus] when Ahab ben Omri perished here was ‘song’. But does the Holy One, blessed be He, rejoice over the downfall of the wicked? Is it not written, [That they should praise] as they went out before the army, and say, “Give thanks unto the Lord for His mercy endures forever;” concerning which R. Yonatan asked: Why are the words, “He is good” mitted from this expression of thanks? Because the Holy One, blessed be He, does not rejoice in the downfall of the wicked. For R. Shmuel bar Nahman said in R. Yonatan‘s name: What is meant by, “And one did not come near the other all night?” In that hour the ministering angels wished to utter the song [of praise] before the Holy One, blessed be He, but He rebuked them, saying: My handiwork [the Egyptians] is drowning in the sea; and you recite a song before me!

מגילה י׳ ב:כ״ה-כ״ח

ומי חדי הקב"ה במפלתן של רשעים והא כתיב (דברי הימים ב כ, כא) בצאת לפני החלוץ ואומרים הודו לה' כי לעולם חסדו וא"ר יוחנן מפני מה לא נאמר כי טוב בהודאה זו לפי שאין הקב"ה שמח במפלתן של רשעים ואמר רבי יוחנן מאי דכתיב (שמות יד, כ) ולא קרב זה אל זה כל הלילה בקשו מלאכי השרת לומר שירה אמר הקב"ה מעשה ידי טובעין בים ואתם אומרים שירה אמר רבי אלעזר הוא אינו שש אבל אחרים משיש ודיקא נמי דכתיב כן ישיש ולא כתיב ישוש ש"מ רבי אבא בר כהנא פתח לה פיתחא להאי פרשתא מהכא (קהלת ב, כו) לאדם שטוב לפניו נתן חכמה ודעת ושמחה זה מרדכי הצדיק ולחוטא נתן ענין לאסוף ולכנוס זה המן לתת לטוב לפני האלהים זה מרדכי ואסתר דכתיב ותשם אסתר את מרדכי על בית המן

Megillah 10b:25-28

Rabbi Yehoshua ben Levi asked: Does the Holy One, Blessed be He, in fact rejoice over the downfall of the wicked? But it is written: “As they went out before the army, and say: Give thanks to the Lord, for His kindness endures forever” (II Chronicles 20:21), and Rabbi Yoḥanan said: For what reason were the words: “for He is good” not stated in this statement of thanksgiving, as the classic formulation is: “Give thanks to the Lord; for He is good; for His kindness endures forever” (I Chronicles 16:34)? Because the Holy One, Blessed be He, does not rejoice over the downfall of the wicked. Since this song was sung in the aftermath of a military victory, which involved the downfall of the wicked, the name of God was not mentioned for the good. And similarly, Rabbi Yoḥanan said: What is the meaning of that which is written: “And the one came not near the other all the night” (Exodus 14:20)? The ministering angels wanted to sing their song, for the angels would sing songs to each other, as it states: “And they called out to each other and said” (Isaiah 6:3), but the Holy One, Blessed be He, said: The work of My hands, the Egyptians, are drowning at sea, and you wish to say songs? This indicates that God does not rejoice over the downfall of the wicked. Rabbi Elazar said that this is how the matter is to be understood: Indeed, God Himself does not rejoice over the downfall of the wicked, but He causes others to rejoice. The Gemara comments: One can learn from the language of the verse as well, as it is written: “So the Lord will rejoice [ken yasis]” (Deuteronomy 28:63). And it is not written yasus, the grammatical form of the verb meaning: He will rejoice. Rather, it is written yasis. The grammatical form of this verb indicates that one causes another to rejoice. Consequently, these words are understood to mean that God will cause others to rejoice. The Gemara concludes: Indeed, learn from it that this is the case. Rabbi Abba bar Kahana introduced this passage with an introduction from here. The verse states with regard to God’s reward to the righteous: “He gives to a man that is good in His sight wisdom, and knowledge, and joy” (Ecclesiastes 2:26). The Gemara explains that this verse is referring to the righteous Mordecai. With regard to the next part of the verse: “But to the sinner He gives the task of gathering and heaping up,” this is referring to Haman. The conclusion of the verse states: “That he may give it to one who is good before God” (Ecclesiastes 2:26). This is Mordecai and Esther, as it is written: “And Esther set Mordecai over the house of Haman” (Esther 8:2).

ברכות י׳ א:ב׳-ד׳

הָנְהוּ בִּרְיוֹנֵי דַּהֲווֹ בְּשִׁבָבוּתֵיהּ דְּרַבִּי מֵאִיר וַהֲווֹ קָא מְצַעֲרוּ לֵיהּ טוּבָא. הֲוָה קָא בָּעֵי רַבִּי מֵאִיר רַחֲמֵי עִלָּוַיְהוּ כִּי הֵיכִי דְּלֵימוּתוּ. אָמְרָה לֵיהּ בְּרוּרְיָא דְּבֵיתְהוּ: מַאי דַּעְתָּךְ — מִשּׁוּם דִּכְתִיב ״יִתַּמּוּ חַטָּאִים״, מִי כְּתִיב ״חוֹטְאִים״? ״חַטָּאִים״ כְּתִיב. וְעוֹד, שְׁפֵיל לְסֵיפֵיהּ דִּקְרָא ״וּרְשָׁעִים עוֹד אֵינָם״, כֵּיוָן דְּ״יִתַּמּוּ חַטָּאִים״ ״וּרְשָׁעִים עוֹד אֵינָם״? אֶלָּא בְּעִי רַחֲמֵי עִלָּוַיְהוּ דְּלַהְדְּרוּ בִּתְשׁוּבָה, ״וּרְשָׁעִים עוֹד אֵינָם״. בְּעָא רַחֲמֵי עִלָּוַיְהוּ, וַהֲדַרוּ בִּתְשׁוּבָה.

Berakhot 10a:2-4

There were these hooligans in Rabbi Meir’s neighborhood who caused him a great deal of anguish. Rabbi Meir prayed for God to have mercy on them, that they should die. Rabbi Meir’s wife, Berurya, said to him: What is your thinking? On what basis do you pray for the death of these hooligans? Do you base yourself on the verse, as it is written: “Let sins cease from the land” (Psalms 104:35), which you interpret to mean that the world would be better if the wicked were destroyed? But is it written, let sinners cease?” Let sins cease, is written. One should pray for an end to their transgressions, not for the demise of the transgressors themselves. Moreover, go to the end of the verse, where it says: “And the wicked will be no more.” If, as you suggest, transgressions shall cease refers to the demise of the evildoers, how is it possible that the wicked will be no more, i.e., that they will no longer be evil? Rather, pray for God to have mercy on them, that they should repent, as if they repent, then the wicked will be no more, as they will have repented. Rabbi Meir saw that Berurya was correct and he prayed for God to have mercy on them, and they repented.

משנה אבות ד׳:י״ט

(יט) שְׁמוּאֵל הַקָּטָן אוֹמֵר, (משלי כד) בִּנְפֹל אוֹיִבְךָ אַל תִּשְׂמָח וּבִכָּשְׁלוֹ אַל יָגֵל לִבֶּךָ, פֶּן יִרְאֶה ה' וְרַע בְּעֵינָיו וְהֵשִׁיב מֵעָלָיו אַפּוֹ:

Pirkei Avot 4:19

(19) Shmuel the Younger says: (Proverbs 24:17-18) "When your enemy falls, do not be happy, and when he stumbles, let your heart not rejoice. Lest God see and it be bad in His eyes and He turn from him [the enemy] His anger."

Rabbi Shai Held

The ideal and the best case scenario is for the wicked man who is ill to have both his body healed and his soul transformed. When that seems impossible (say, because the person in question has a truly intractable personality disorder), then I think it best to pray that Hashem do whatever Hashem deems necessary to prevent the wicked person from enacting his wicked plans, or from (further) damaging and endangering others. We should not dictate to Hashem the means of salvation Hashem will use; we should only pray for the salvation and leave those decisions in God's hands.

ספר החינוך כ״א:א׳

מצות ספור יציאת מצרים - לספר בענין יציאת מצרים בליל ט''ו בניסן, כל אחד כפי צחות לשונו, ולהלל ולשבח לשם יתברך על כל הנסים שעשה לנו שם. שנאמר (שמות יג ח) והגדת לבנך. וכבר פרשו חכמים, (מכילתא בא שם) דמצות הגדה זו הוא בליל ט''ו בניסן בשעת אכילת מצה. ומה שאמר הכתוב לבנך, לאו דוקא בנו, (פסחים קטז, א) אלא אפילו עם כל בריה.

Sefer HaChinukh 21:1

The commandment to recount the exodus from Egypt: To tell about the exodus from Egypt on the night of the fifteenth of Nissan (the first night of Pesach) - each person according to his own power of expression - to laud and to praise God, may He be blessed, for all the miracles He performed for us there, as it is stated (Exodus 13:8), "And you shall tell your son." [Although the verse doesn't specify when this should be done,] the Sages have already explained (Mekhilta d'Rabbi Yishmael 13:8) that this commandment of retelling is on the night of the fifteenth of Nissan - which is the time of the eating of the matsah. And that which the verse states, "[and you shall tell] your son," [does not mean] exclusively one's son; but rather even with any creature (Pesachim 116a).