David HaMelech says (Tehillim 80:14):
יְכַרְ סְמֶנָּה חֲזִיר מִ י עַ ר וְזִיז שָׂדַי יִ רְ עֶ נּ ָה׃
The boar out of the wood ravages it, and the wild beast of the field devours it.
Who is this boar? Chazal say (Yalkut Shimoni, Tehillim 829), this is Eisav the wicked. And why specifically is Eisav the wicked likened to a boar? The Midrash says (Bereishit Rabbah, 65:1), when the boar lies down, it stretches out its hooves as if to say, "I am pure." So too, this wicked kingdom robs and plunders yet appears as if it is setting up the stage. Thus, Eisav, for forty years, hunted men’s wives and violated them, and when he reached the age of forty, he likened himself to his father, saying, "Just as my father married a woman at forty, so too I will marry a woman at forty – וַיְהִ י עֵשָׂו בֶּן אַרְ בָּעִים שׁ ָנָה.
The sefer Manot HaLevi by Rav Shlomo Alkabetz provides a wonderful idea. The "ע" of יְכַרְ סְמֶנָּה חֲזִיר מִ י עַר is suspended high, leaving מיר and the numerical value of עמלק – Amalek. From there until the end of the perek there are fifty words, and the tree in Megillat Esther was fifty cubits high, hinting at Haman, as it says: פ ְ שׁ ִ י 'מַּסְגֵּר נַ 'ו ֹצִ יאָ ה מִ 'ה – המן.
The sefer Iggeret HaPurim brings the words of the Maharsha (Kiddushin 30). The Maharsha writes, the "ע" of יְכַרְ סְמֶנָּה חֲזִיר מִ י עַר is the midpoint of the letters in Tehillim, because it was established in Tefillah to nullify the power of Eisav, which is the power of impurity of the primordial snake. Therefore, the division and break come in the letters of עַ ר חֲ זִ יר מִ י, which is the power of Eisav, as stated in the Midrashim.
Not only is Eisav a boar, but Haman is too! The Midrash (Esther Rabbah, 7:1) provides the parable of a man who had a filly (סְ יָחָ ה), a female donkey (חֲ מו ֹרָ ה), and a sow (חֲ זִ ירָ ה). He would feed the sow without limit, but the filly and the donkey only measured amounts. The filly said to the donkey, "What is this fool doing? We, who do the work of the master of the house, he gives us limited amounts, but to the pig, who is idle, he gives pot after pot!" The donkey replied to the filly, "The time will come and you will witness her downfall, as they are not feeding it for its benefit, but rather, to its detriment." When the calends – a feast day at the start of every Roman month – arrived, they immediately took the pig, slaughtered her, and put her on a shawarma spit. They began giving barley to the donkey’s daughter, but she snorted at it and didn’t eat. Her mother said to her, "My daughter, it’s not the food that causes this, but idleness causes it," as is written in Megillat Esther: וַי שֶׂם אֶת כִּסְּאוֹ מֵעַל כָּל הַשָּׂרִים אֲשׁ ֶר אִתּוֹ – And he placed his throne above all the princes who were with him, and the result was וַי תְ לוּ אֶ ת הָ מָ ן – And they hanged Haman.
The Chida writes (Yosef Tehillot): יְ כַ רְ סְ מֶ נּ ָה can be rearranged to spell יִסָּ כֵר הָמָ ן, as in שׁ ָ ק ֶ ר יִסּ ָ כֵ ר פִּ י דו ֹבְ רֵ י – For the mouth of those who speak lies shall be stopped. A boar shows its hooves, so too Haman told Achashveirosh that it was for his benefit that he sought to destroy Am Yisrael, and therefore his end was to be hanged fifty high.
The Chida, in Nachal Sorek, provides another wonderful idea. כִּי עַיִן בְּעַיִן יִרְ אוּ בְּשׁ וּב ה' צִי וֹן – For eye to eye they will see when Hashem returns to Zion. The earlier sages explained that the ע of יְכַרְ סְמֶנָּה חֲזִיר מִ י עַר is small and suspended, while the ע of שׁ ְ מ ַ ע is fixed and large. (This is how both appear written on parchment – small and suspended versus in place and large.) By the merit of the "עַיִן" of שׁ ְ מ ַ ע, the "עַיִן" of יְכַרְ סְמֶנָּה חֲזִיר מִ י עַר, which hints at Eisav, will be nullified. This is what כִּי עַיִן בְּעַיִן יִרְ אוּ בְּשׁ וּב ה' צִי וֹן means. Based on these words, we can answer the question; Why did Haman care if Mordechai recited Shema? It is because when Shema is recited, the large ע of שׁ ְ מ ַ ע nullifies the ע of יְכַרְ סְמֶנָּה חֲזִיר מִ י עַר, which is Amalek!
