אָמַר רַבִּי יְהוֹשֻׁעַ בֶּן לֵוִי: אַף עַל פִּי שֶׁקָּרָא אָדָם קְרִיאַת שְׁמַע בְּבֵית הַכְּנֶסֶת — מִצְוָה לִקְרוֹתוֹ עַל מִטָּתוֹ. אָמַר רַבִּי יוֹסֵי: מַאי קְרָא — ״רִגְזוּ וְאַל תֶּחֱטָאוּ אִמְרוּ בִלְבַבְכֶם עַל מִשְׁכַּבְכֶם וְדֹמּוּ סֶלָה״.
Rabbi Yehoshua ben Levi said: Even though one recited Shema in the synagogue, it is a mitzva to recite it upon his bed in fulfillment of the verse: “When you lie down.” Rabbi Yosei said: What verse alludes to the fact that one must recite Shema in the evening, upon his bed, as well? “Tremble, and do not sin; say to your heart upon your bed and be still, Selah” (Psalms 4:5). This is understood to mean: Recite Shema, about which it is written, “on your hearts,” upon your bed, and afterward be still and sleep.
אָמַר רַבִּי יִצְחָק: כׇּל הַקּוֹרֵא קְרִיאַת שְׁמַע עַל מִטָּתוֹ, כְּאִלּוּ אוֹחֵז חֶרֶב שֶׁל שְׁתֵּי פִיּוֹת בְּיָדוֹ. שֶׁנֶּאֱמַר: ״רוֹמְמוֹת אֵל בִּגְרוֹנָם וְחֶרֶב פִּיפִיּוֹת בְּיָדָם״, מַאי מַשְׁמַע? אָמַר מָר זוּטְרָא וְאִיתֵּימָא רַב אָשֵׁי: מֵרֵישָׁא דְעִנְיָנָא, דִּכְתִיב: ״יַעְלְזוּ חֲסִידִים בְּכָבוֹד יְרַנְּנוּ עַל מִשְׁכְּבוֹתָם״. וּכְתִיב בָּתְרֵיהּ: ״רוֹמְמוֹת אֵל בִּגְרוֹנָם וְחֶרֶב פִּיפִיּוֹת בְּיָדָם״.
The Gemara continues its treatment of the recitation of Shema upon one’s bed. Rabbi Yitzḥak said: Anyone who recites Shema on his bed, it is as if he holds a double-edged sword, guarding him from all evil, as it is stated: “High praises of God in their mouths, and a double-edged sword in their hands” (Psalms 149:6). The Gemara asks: From where is it inferred that this verse from Psalms refers to the recitation of Shema? Mar Zutra, and some say Rav Ashi, said: We derive it from the preceding verse, as it is written: “Let the pious exult in glory; let them joyously sing upon their beds.” The praise of God from one’s bed is the recitation of Shema. And it is written thereafter: “High praises of God in their mouths, and a double-edged sword in their hands.”
ויקרא קריאת שמע, וצריך לדקדק בקריאת שמע שעל מטתו כמו בק"ש בבית הכנסת. ויקראנה באימה וביראה ובכוונה עצומה, כי רבים אומרים שעיקר קריאת שמע שאדם יוצא בה הוא במה שקורא לפני מטתו.
And you must read the Shema- you must be very meticulous with the reading of the Shema before sleep as carefully as the one recited in synagogue. You must read it with awe and fear and tremendous concentration, because many opinions hold that the main Shema with which one fulfills their obligation is the one recited before bedtime.