I heard that a person should say all 3 paragraphs of Shema before sof z'man kriyat sh'ma if their shul starts after sof z'man kriyat sh'ma. What's the source for the need to say all three p'rakim to be yotzei?
1Hi Shalom. Are you asking about saying all three as opposed to saying fewer? I'm a bit confused what exactly you're looking for. For instance, do you know what "zman kriat shema" means? And I assume you're talking about the morning shema?– Double AA ♦Mar 15, 2021 at 15:44
I heard from someone that you say all 3 paragraphs of shema if your shul starts after zman tefilla (like if zman is 930 and your shul starts at 10, you would say shema before 930 with all 3 paragraphs (shema, vehaya, vayomer). I'm wondering what the source is for saying 3 paragraphs instead of just saying the first paragraph of shema for intance.– Shalom FeuerMar 15, 2021 at 17:17
The obligation to say all three parshiyos to fulfil the obligation of kriyas shema is found in Berachos 13a.
There is a dispute among the Rishonim if the biblical obligation requires all three parshiyos; there are many opinions defining the biblical obligation: the first verse (Ramban, Sefer HaChinuch), the first paragraph (Rashi); the first two paragraphs (Rabeinu Yona, IIRC); or all three (Rambam). [Some hold that biblically, one can fulfil the obligation with any parsha, and the institution to fulfil the obligation with these three specifically is Rabbinic in origin]
All agree, however, that there is an obligation to read all three daily.
1It's not clear all require all three to be read before the zman (though clearly that is the simple read of most sources). For instance, if Rashi holds that the second two paragraphs can be read before the zman at night, presumably the same could apply to reading them late in the morning.– Double AA ♦Mar 15, 2021 at 17:51
Ya thats really my main question. I know the chiyuv is to say all three but whats the source that all three need to be said before zman? Like maybe only the deoraisa ones need to be before zman? Mar 15, 2021 at 19:44
1@ShalomFeuer Do you see how no one could tell from your original post that that is what you wanted to know?– Double AA ♦Mar 15, 2021 at 20:00
@ShalomFeuer The reasoning seems pretty simple to me. The time for fulfilling the mitzvah of Krias Shma is in the morning before the zman. Chazal defined the mitzvah as saying these three paragraphs. Ergo, all three paragraphs must be said before the zman. QED– N.T.Mar 18, 2021 at 8:21