סימן יז סעיף א

הַתְחָלַת זְמַן קְרִיאַת שְׁמַע שֶׁל שַׁחֲרִית, הוּא כְּמוֹ זְמַן תְּפִלִּין, וְנִמְשָׁךְ זְמַנָּהּ עַד רְבִיעִית הַיּוֹם, בֵּין שֶׁהַיּוֹם אָרֹךְ בֵּין שֶׁהוּא קָצָר, וְנֶחְשָׁב הַיּוֹם מִן עֲלוֹת עַד צֵאת הַכּוֹכָבִים, וּמִצְוָה מִן הַמֻּבְחָר לִקְרֹת כַּוָּתִיקִים, (הַמְחַבְּבִים אֵת הַמִצְוֹת) שֶׁהָיוּ מְכַוְּנִים לִקְרֹתָהּ מְעַט קוֹדֵם הַנֵּץ הַחַמָּה כְּדֵי שֶׁיְסַיֵּם קְרִיאַת שְׁמַע וּבִרְכוֹתֶיהָ עִם הַנֵּץ הַחַמָּה, וְיִסְמֹךְ לָהּ הַתְּפִלָּה, וּמִי שֶׁיּוּכַל לְכַוֵּן לַעֲשׂוֹת כֵּן שְׂכָרוֹ מְרֻבֶּה מְאֹד, וְעַל כָּל פָּנִים צְרִיכִין לִזָּהֵר מְאֹד, שֶׁלֹּא לְאַחֵר הַזְּמַן מֵרְבִיעִית הַיּוֹם, וּבִפְרָט בִּימוֹת הַקַּיִץ, כְּשֶׁהַיּוֹם אָרֹךְ בִּמְדִינָתֵנוּ, לִפְעָמִים סוֹף הַזְּמַן הוּא קוֹדֵם "זִיבֶּען אוּהֶר", וּמִכָּל מָקוֹם בְּדִיעֲבַד אִם עָבַר הַזְּמָן, מֻתָּר לִקְרֹת קְרִיאַת שְׁמַע עִם בִּרְכוֹתֶיהָ עַד שְׁלִישׁ הַיּוֹם, אֲבָל לְאַחַר שְׁלִישׁ הַיּוֹם, אָסוּר לוֹמַר הַבְּרָכוֹת אֶלָּא אוֹמֵר קְרִיאַת שְׁמַע לְבַד וַאֲפִלּוּ כָּל הַיּוֹם (וְיֵשׁ אוֹמְרִים דְּגַם הַבְּרָכוֹת יָכוֹל לוֹמַר כָּל הַיּוֹם פר"ח). (נ"ח).

The earliest time for reading the morning Shema is the same as that for putting on tefillin,¹When there is sufficient light to recognize a slight acquaintance at a distance of six feet, you may read the Shema. (See Chapter 10 section 2) and the time period extends until the end of the first quarter of the day, regardless if the day is long or short. The length of the day is reckoned from daybreak until the stars²This refers to three medium size stars. are visible.³The Gra (Vilna Gaon) holds that the day is reckoned from sunrise to sunset. Assuming that from daybreak to sunrise is 72 minutes, and from sunset to the visibility of the stars is 72 minutes, the time of reading the Shema is extended by 36 minutes! The commandment is fulfilled in its excellence when it is read in the manner of the Vasikin (these were pious men who treasured the mitzvos) who were careful to read it shortly before sunrise, in order to complete the Shema and its berachos at sunrise, and proceed with the Amidah immediately thereafter. He who is able to accomplish this, will merit great reward. In any case, you must be very careful not to delay [reading Shema] past the first quarter of the day, especially during the summer when the days are long. In our country, the latest time [for reading the Shema] is before seven o'clock [in the morning.]⁴This applied to Hungary where the author resided. Nevertheless, as a last resort, if the time limit has passed, you are permitted to read the Shema with its berachos until one third of the day. However, after one third of the day it is forbidden to recite the berachos but the Shema itself may be read at any hour of the day. (Some authorities hold that the berachos⁵This is the opinion of Rambam and Pri Chadash. may also be recited the entire day.⁶There is a third opinion that the berachos may be recited only till noon.)

תנא דבי אליהו כל השונה הלכות בכל יום מובטח לו שהוא בן העולם הבא שנאמר הליכות עולם לו אל תקרי הליכות אלא הלכות (נדה ע"ג.)