Is Maariv optional? And why is it not repeated out loud like the daytime prayers?
Short answer: the accepted ruling is that it is not a full obligation, but the Jewish people took it on as one anyway. The Gemara records the argument. Rabban Gamliel said the evening prayer is an obligation. Rabbi Yehoshua, another leading sage of that generation, said it is optional. Abaye ruled like the first view and Rava like the second (Berakhot 27b). Abudarham says the law follows Rava.
The Gemara tells a story. A student asked both of them and got two answers. When he asked again in front of the whole study hall, Rabban Gamliel asked if anyone disagreed. Rabbi Yehoshua said no one did. Rabban Gamliel answered that he had been told Rabbi Yehoshua said optional. Rabbi Yehoshua stood up and admitted it.
Where did the prayer come from? The Avot and Parashat HaTamid pages tell the Gemara's two answers: Yaakov set it, or it matches the daily Temple offerings (Berakhot 26b). One detail matters here. The limbs and fats of the day's offerings kept burning all night, so the Gemara says the evening prayer has no fixed time.
The Rambam (Maimonides, who wrote a great code of Jewish law in the 1100s) rules that the evening prayer is not an obligation like the morning and afternoon prayers. But Jews in every place took it on as one (Laws of Prayer 1:6). Abudarham quotes the Rif (Rabbi Yitzchak Alfasi, an early authority on Jewish law, 1000s): even the view that calls it optional still counts it as a mitzvah, and today everyone treats it as an obligation.
You can see the history in the room. The Shulchan Aruch (the main code of Jewish law) says the leader does not repeat the Amidah at Maariv. The Mishnah Berurah (a central commentary on daily Jewish law, written around 1900) says why: it was never a full obligation, only a mitzvah, so nobody needs the leader to say it for them. Even now that people treat it as an obligation, the custom was not strong enough to burden the congregation with a repetition.
Berakhot 26b,Berakhot 27b,Rambam, Laws of Prayer 1:6,Abudarham, Weekday Prayers, Evening Service,Shulchan Aruch, Orach Chaim 237:1,Mishnah Berurah 237:1My friend's siddur ends this blessing differently. Who is right?
Our siddur ends with: "Hashem of hosts is His name. God, living and enduring, will always rule over us, forever and ever." Then comes the closing, "who brings in the evenings." Some customs skip those added lines, or keep only the first one.
The Tur says the Spanish wording of his day went straight from "separates between day and night" to the closing, and the added lines were the Ashkenaz way. (Our siddur is called Sefard, but it has those lines.) His brother, Rabbi Yechiel, wrote that the Spanish way is more correct, because the added words are "not like the closing, right next to the closing." Abudarham calls the addition a mistake for the same reason. The rule behind it, as the Ritva (a Spanish commentator on the Gemara, around 1300) puts it: just before a blessing closes, say something like its closing.
The Tur's father, the Rosh (Rabbi Asher ben Yechiel, a leading authority on Jewish law, who died in 1327), defended the custom. We pray "Hashem will rule forever and ever." When that comes true, so will the verse "at evening time there will be light" (Zechariah 14:7). So the lines are, in a way, like the closing. The Arukh HaShulchan adds that exile is like night, and we ask that God's kingship soon shine on us.
The Arukh HaShulchan also explains the line before it. "Hashem of hosts" means God set His hosts in this order, and the stars are in His hand like an axe in a woodcutter's hand, with no power of their own.
A third custom: the Kaf HaChaim (a Sephardic code of daily Jewish law, printed in Jerusalem in the early 1900s) says Sephardim in his day added only "Hashem of hosts is His name," because the Sha'ar HaKavanot (a Kabbalistic work) mentions it. So different communities kept different endings, and the old authorities argued about it.
Tur, Orach Chaim 236,Abudarham, Weekday Prayers, Evening Service,Ritva on Pesachim 104a,Zechariah 14:7,Arukh HaShulchan, Orach Chaim 236:2-3,Kaf HaChaim, Orach Chaim 236:2The blessing says God "rolls light away." Where does the light actually go?
The morning prayer Yotzer Or already explains why this blessing mentions day at night. This question is about one word: golel, "rolls."
Abudarham says golel comes from "they rolled the stone" (Bereishit 29:3) and means "removes." On the next words, "makes day pass and brings night," he adds that God does not take the sun and carry it off somewhere else. Instead God separates day from night, and the earth stands between them. When it is light for us, it is dark below the earth. When it is dark for us, it is light below the earth.
The Arukh HaShulchan (late 1800s) hears the same idea in the word itself. The earth is a ball, he writes, so there is never a moment without day somewhere and night somewhere else. "Rolls" fits, as if the sun were rolling around the ball. In one place light pushes darkness away, and in another darkness pushes light away, never stopping. That is why, he says, the blessing first speaks of the stars set in their places by God's will.
These are commentators explaining a word. The Gemara itself uses these words for one thing: to show that the blessing mentions day at night (Berakhot 11b). Both commentators say the light does not disappear when it leaves you. Abudarham puts it below the earth. The Arukh HaShulchan puts it on the other side of the ball.
Abudarham, Weekday Prayers, Evening Service,Bereishit 29:3,Arukh HaShulchan, Orach Chaim 236:2,Berakhot 11b