The Torah describes how a slave who doesn't want to leave his master (by Shmitah) has to get pierced through his ear:
Exodus 21:6
וְהִגִּישׁ֤וֹ אֲדֹנָיו֙ אֶל־הָ֣אֱלֹהִ֔ים וְהִגִּישׁוֹ֙ אֶל־הַדֶּ֔לֶת א֖וֹ אֶל־הַמְּזוּזָ֑ה וְרָצַ֨ע אֲדֹנָ֤יו אֶת־אָזְנוֹ֙ בַּמַּרְצֵ֔עַ וַעֲבָד֖וֹ לְעֹלָֽם׃
His master shall take him before God. He shall be brought to the door or the doorpost, and his master shall pierce his ear with an awl; and he shall then remain his master’s slave for life.
The reason why the slave is pierced specifically through his ear is explained by Rashi:
Rashi Exodus 21:6
ורצע אדניו את אזנו במרצע. הַיְמָנִית, אוֹ אֵינוֹ, אֶלָּא שֶׁל שְׂמֹאל? תַּ"לֹ אֹזֶן אֹזֶן לִגְזֵרָה שָׁוָה, נֶאֱמַר כָּאן וְרָצַע אֲדֹנָיו אֶת אָזְנוֹ, וְנֶאֱמַר בִּמְצֹרָע תְּנוּךְ אֹזֶן הַמִּטַּהֵר הַיְמָנִית (ויקרא י"ד), מַה לְּהַלָּן הַיְמָנִית, אַף כָּאן הַיְמָנִית; וּמָה רָאָה אֹזֶן לֵרָצַע מִכָּל שְׁאָר אֵבָרִים שֶׁבַּגּוּף? אָמַר רַבָּן יוֹחָנָן בֶּן זַכַּאי: אֹזֶן זֹאת שֶׁשָּׁמְעָה עַל הַר סִינַי לֹא תִגְנֹב, וְהָלַךְ וְגָנַב, תֵּרָצַע. וְאִם מוֹכֵר עַצְמוֹ, אֹזֶן שֶׁשָּׁמְעָה עַל הַר סִינַי כִּי לִי בְנֵי יִשְׂרָאֵל עֲבָדִים, וְהָלַךְ וְקָנָה אָדוֹן לְעַצְמוֹ, תֵּרָצַע. רַבִּי שִׁמְעוֹן הָיָה דּוֹרֵשׁ מִקְרָא זֶה כְּמִין חֹמֶר: מַה נִּשְׁתַּנּוּ דֶּלֶת וּמְזוּזָה מִכָּל כֵּלִים שֶׁבַּבַּיִת? אָמַר הַקָּבָּ"ה דֶּלֶת וּמְזוּזָה שֶׁהָיוּ עֵדִים בְּמִצְרַיִם כְּשֶׁפָּסַחְתִּי עַל הַמַּשְׁקוֹף וְעַל שְׁתֵּי הַמְּזוּזוֹת וְאָמַרְתִּי כִּי לִי בְנֵי יִשְׂרָאֵל עֲבָדִים – עֲבָדַי הֵם וְלֹא עֲבָדִים לַעֲבָדִים – וְהָלַךְ זֶה וְקָנָה אָדוֹן לְעַצְמוֹ, יֵרָצַע בִּפְנֵיהֶם (קידושין כ"ב):
AND HIS LORD SHALL BORE HIS EAR THROUGH WITH THE AWL — “His ear” means his right ear. Or perhaps this is not so, but Scripture means his left ear? Scripture however uses the term אזן here and it uses אזן in another passage, thereby suggesting an analogy based upon verbal similarity; viz., here it is said “and his lord shall bore his ear (אזנו) through”, and of the leper it is said, (Leviticus 14:25) “and the priest shall put it upon the tip of the right ear (אזנו הימית) of him that is to be cleansed”. — How is it in that latter passage? It is the right ear! So here, too, it is the right ear. — What is the reason that the ear had to be pierced rather than any other limb of the servant’s body? Rabban Jochanan ben Zaccai said: That ear which heard on Mount Sinai, (Exodus 20:13) “Thou shalt not steal” and yet its owner went and stole and was therefore sold as a slave — let it be pierced! Or, in the case of him who sold himself from destitution, having committed no theft, the reason is: That ear which heard on Mount Sinai what I said, (Leviticus 25:55) “For unto Me the children Israel are servants” and yet its owner went and procured for himself another master — let it be pierced! (Mekhilta d'Rabbi Yishmael 21:6:3; Kiddushin 22b). Rabbi Simeon interpreted this verse like a jewel (i. e. giving it an ethical signification): In what respect are door and doorpost different from all other objects in the house that they should be singled out for this purpose? God, in effect, said: door and doorpost that were eye-witnesses in Egypt when I passed over the lintel and the two doorposts, freeing Israel from slavery, and when I said, (Leviticus 25:55) “For unto Me the children of Israel are servants” — servants to Me but not servants of servants (of human beings), and yet this man went and procured another master for himself — let him be pieced in their presence (i. e. let them be eye-witnesses now when this man voluntarily prolongs his state of slavery)! (Kiddushin 22b.)
Rashi seems to be explaining that the reason why the slave was pierced through the ear is because the same ear that herd what G-d said by Har Sinai, and yet disobeid him, should be pierced.
Yet, we find by the giving of the Torah:
Exodus 20:15
וְכָל־הָעָם֩ רֹאִ֨ים אֶת־הַקּוֹלֹ֜ת וְאֶת־הַלַּפִּידִ֗ם וְאֵת֙ ק֣וֹל הַשֹּׁפָ֔ר וְאֶת־הָהָ֖ר עָשֵׁ֑ן וַיַּ֤רְא הָעָם֙ וַיָּנֻ֔עוּ וַיַּֽעַמְד֖וּ מֵֽרָחֹֽק׃
All the people witnessed the thunder and lightning, the blare of the horn and the mountain smoking; and when the people saw it, they fell back and stood at a distance.
And Rashi explains:
ראים את הקולת. רוֹאִין אֶת הַנִּשְׁמָע, שֶׁאִי אֶפְשָׁר לִרְאוֹת בְּמָקוֹם אַחֵר:
[THEY] SAW THE SOUNDS — they saw that which should be heard (Mekhilta d'Rabbi Yishmael 20:15:1) — something which is impossible to see on any other occasion.
So the Jewish people saw the giving of the Torah in a way which was never seen and can't be seen again.
They also saw things which are meant to be heard!
G-d wanted to punish the slave in the exact limb which disobeid him. More unique to the giving of the Torah, was the fact that the Jews saw things that weren't usually seen.
So why didn't the slave get pierced in the eye?
