Gemara
Q1: Why not tell us there is chiyuv before saying meieimasa
Q2: WHy maariv first, not Shacharis?
A2: Pasuk says beshachbecha first, not uvkumecha.
A1: Read it: We say shma at night. When can we begin to say it?
A2b: follows briyas ha'Olam.
Why is A2 before A1 if Mishna Avos says "al rishon rishon v'al acharon acharon? And see in Chayei Sarah, Rivka was praised for answering "who is your father? Do you have place for us to sleep?" in order? I don't have an answer, though see ibn Ezra to Yoel 3:3:
ונתתי - מנהג אנשי לשון הקודש , כאשר יזכירו שנים דברים , יחל לספר דברי השיני בתחלה , ואחר כן ישוב אל הראשון באחרונה; כמו "לך יום אף לך לילה" (תה' עד , טז); "ואתן ליצחק את יעקב ואת עשו" (יהו' כד , ד); וככה זה: ונתתי דם - בארץ , ובשמים - אש ותימרות עשן.
ibnEzra that lashon chachamim is diff from lashon Psukim. I thought of answering with Chulin 137b that chazal use diff words than torah. But it doesn’t really answer it b/c that’s for use of one word. This is an entire style. See Tos Yom Tov Terumos 1:1. Also, Rivka answered Eliezer "al rishon rishon v'al acharon acharon." (Breishis 24:24) And Rashi shemos 3:12 is al rishon rishon v’al acharon acharon.
ונתתי - מנהג אנשי לשון הקודש , כאשר יזכירו שנים דברים , יחל לספר דברי השיני בתחלה , ואחר כן ישוב אל הראשון באחרונה; כמו "לך יום אף לך לילה" (תה' עד , טז); "ואתן ליצחק את יעקב ואת עשו" (יהו' כד , ד); וככה זה: ונתתי דם - בארץ , ובשמים - אש ותימרות עשן.
ibnEzra that lashon chachamim is diff from lashon Psukim. I thought of answering with Chulin 137b that chazal use diff words than torah. But it doesn’t really answer it b/c that’s for use of one word. This is an entire style. See Tos Yom Tov Terumos 1:1. Also, Rivka answered Eliezer "al rishon rishon v'al acharon acharon." (Breishis 24:24) And Rashi shemos 3:12 is al rishon rishon v’al acharon acharon.
I'll suggest another possible answer - when a katan becomes a gadol the first mitzvah that is chal would be kriyas shma of arvis.
Bein Hashmashos based on http://www.yutorah.org/lectures/lecture.cfm/710224/Rabbi_Daniel_Z-_Feldman/Halakhic_Night#
Ø Shabbat 34b, the period of bein ha-sh’mashot (in between sh’kia and tzet hakokhavim) is identified by R. Yehudah as three quarters of a mil
Ø Pesachim 94a. There, in a discussion concerning the dimensions of the Earth, R. Yehudah states that in between sh’kia and tzet hakokhavim there are four mil
Ø (See Resp. Maharam Alashkar, 96, citing R. Sherira Gaon and R. Hai Gaon) and the Gra (see Biur to Sulchan Arukh, 261:2) represent different versions, the statement in Pesachim is not applicable to the halakhah in these cases. Thus, ¾ of a mil after shkia is tzet hakokhavim, and the time in between is bein hashmashot.
Ø Rabbeinu Tam (see Tosafot, Berakhot 2b, s.v. dilma; Shabbat 35a, s.v. trei; Pesachim 94a, s.v. R. Yehudah), however, resolves the issue differently. In his assessment, there are actually two points called sh’kia The first sh’kia takes place when the sun begins to sink beneath the horizon The second sh’kia refers to the point once the sun has already sunk. The four mil period refers to the time in between the first sh’kia and tzet, while the ¾ mil period is the time from the second sh’kia until tzet. (see also Magen Avraham, 331:2, and Resp. Chatam Sofer, O.C. 80). Almost all rishonim - Yabia Omer vol. 2 no. 21
Ø Sefer Yereim, 274 night begins at sunset and that the three quarters of a mil represent the beginning of sunset. At sunset, when the sun falls below the horizon and there is no longer any direct sunlight, it becomes theoretically possible to see stars. Four mil later the stars become visible to everyone. http://www.aishdas.org/toratemet/en_pamphlet4.html
Ø Tosfos Menachos 20 and Shaagas Aryeh 17: dam nifsal misafek.
Ø אמר רבי יוסי: בין השמשות כהרף עין. זה נכנס וזה יוצא ואי אפשר לעמוד עליו (Brachos 2b last line and Shabbos 34b)
Ø See Igros Moshe OC IV 62 – 50 minutes for latitude of NY.; alsoYD IV 17:26
How long is a mil? mil ¾ 3.25 4
Ø 18 minutes ( ) minutes 13.5 58.5 72
Ø 22.5 minutes ( ) 18.875 90
Ø 24 minutes (Rambam, Perush Hamishna Pesachim) 18 72 96
Astronomical Phenomena
Ø Civil Twilight – 6 degrees below Horizon: This is the limit at which twilight illumination is sufficient, under good weather conditions, for terrestrial objects to be clearly distinguished; at the beginning of morning civil twilight, or end of evening civil twilight, the horizon is clearly defined and the brightest stars are visible under good atmospheric conditions in the absence of moonlight or other illumination.
Ø Nautical Twilight – 12 degrees bvelow horizon: At the beginning or end of nautical twilight, under good atmospheric conditions and in the absence of other illumination, general outlines of ground objects may be distinguishable, but detailed outdoor operations are not possible. During nautical twilight the illumination level is such that the horizon is still visible even on a Moonless night allowing mariners to take reliable star sights for navigational purposes, hence the name.
Ø Astronomical Twilight – 18 degrees below horizon: scattered light from the Sun is less than that from starlight and other natural sources. For a considerable interval after the beginning of morning twilight and before the end of evening twilight, sky illumination is so faint that it is practically imperceptible
Parshios Kriyas Shma – see Eynayim Lamishpat p 130 (orig print)
Ø RY Hanasi – pasuk of shma
Ø Rashi 1st para (maybe because it’s connected, but a different parsha can’t be part of it midioraissa)
Ø R Yonah 1st 2 para (since third is flexible – any parsha that mentions Mitzrayim, it cannot be part of the dioraissa) (But at end of 7th perek he says first pasuk or first paragraph)
Ø Rambam and Tos – all 3 (see Siach Hagrid)
Ø And see later Daf 12 about wanting to add 10 dibros to Shma.
