Why does a song of victory include a line about being rejected?
Verse 22 says: "The stone the builders rejected has become the cornerstone." Picture a work crew that tosses one stone aside as useless. Later it turns out to be the stone the whole corner depends on.
The Gemara says Yishai, David's father, said this line. When the prophet Shmuel came to Yishai's house to anoint the next king, Yishai had seven sons walk past. None was chosen. Shmuel asked if those were all, and Yishai said there was still the youngest, out with the sheep (Shmuel I 16:10-13). Rashi says the line means David, who spent his days as a shepherd and became the head. Rashbam (Rashi's grandson) adds that David was the youngest of his brothers.
Rashi also notices that the next verse says "wonderful in our eyes," in the plural. So it is the brothers speaking. They were standing there when Shmuel anointed the one who had been left with the sheep.
The Midrash on Tehillim imagines the talk: yesterday he was herding sheep, and suddenly he is king. David answers with a line from Shir HaShirim (the Song of Songs), "I did not know myself." The same Midrash then tells of a man who carried loads for the nobles and became governor. He tells the people staring at him, "You are amazed at me. I am more amazed than you." That, it says, is how Israel will answer the nations in the future, when they see Israel at peace.
There is a second reading. Radak says that if the Jewish people said it, then the stone is Israel. Kings looked down on them and would not count them as even one of the building stones. But Israel, he says, is the foundation of the world's building through its laws and rulings. Rashi on Tehillim agrees the stone is a people that was low among the nations.
So the sources agree on the shape of it: someone dismissed turns out to be what holds the building up. They differ on who. Rashi himself gives both readings, David in the Gemara and a people in Tehillim.
Pesachim 119a, with Rashi and Rashbam,Shmuel I 16:10-13,Midrash Tehillim 118:21,Radak and Rashi on Tehillim 118:22Why is half of this said twice? Is it just filler?
From "Odecha" ("I thank You") to the end of Hallel, every phrase is said twice. Your siddur prints it twice on purpose. It is a custom, and the Sages knew it was a custom.
The Mishnah (the Sages' earliest teaching, put in writing around the year 200) says it plainly: in a place where they are used to doubling, double, and in a place where they say it once, say it once. The Gemara adds that Rabbi (Rabbi Yehuda HaNasi, who edited the Mishnah) doubled some verses, and Rabbi Elazar ben Perata added more. Abaye explains the addition: doubling from "Odecha" and on. The Rambam (Maimonides, who died in 1204) spells it out: each phrase twice, from "Odecha" to the end of Hallel.
The Gemara does not say why. Later teachers gave reasons. Abudarham (a scholar in Spain in the 1300s who wrote a classic commentary on the prayers) gives two. First, the early part of this passage already comes in pairs. Rashi on Sukkah 38a lists them and gives this same reason: "Hashem is mine" twice, "better to take refuge" twice, "surrounded me" twice. So the passage is finished the same way, and Abudarham links those pairs to this world and the days of the Mashiach. Second, since David, Yishai, the brothers and Shmuel each said a verse, we double them to honor them, as if each verse stood alone.
The Shulchan Aruch (the main code of Jewish law) says that for doubled verses, each place follows its own custom. The Mishnah Berurah (a central commentary on daily Jewish law, written around 1900) says that in our places the custom is to double from "Odecha" to the end of Hallel.
So the answer is a custom with two reasons, not a rule with one. If a friend's shul says these lines once, the Mishnah and the Shulchan Aruch both say to follow the local custom.
Mishnah Sukkah 3:11,Sukkah 39a,Rashi on Sukkah 38a,Rambam, Laws of Megillah and Chanukah 3:11,Abudarham, Rosh Chodesh,Shulchan Aruch, Orach Chaim 422:3,Mishnah Berurah 422:19Does "God disciplined me" mean my suffering was a punishment?
Verse 18 says: "Yah disciplined me hard, but He did not hand me over to death." The Hebrew for "disciplined" comes from the same root as yissurim, the Sages' word for suffering. So it sounds like hard times are God's correction.
Two classic commentators read it that way. Radak says the days of trouble were God's discipline, to clean away the speaker's wrongdoing, not because God wanted him dead. Rashi says the discipline was exile, where all the speaker's sins were atoned for.
But the Gemara does not treat every hardship as a punishment. The Wednesday Song of the Day in this siddur walks through its steps in full. The last step matters here: if a person looks over his deeds, and then at his Torah study, and finds nothing, it is clear these are "sufferings of love," because Hashem rebukes the one He loves (Mishlei 3:12). So the Gemara expects some suffering with no cause the person can find.
The book of Iyov (Job) goes further. His friends argued that suffering must come from a person's own wrongdoing. One of them, Elifaz, says, "Who that was innocent ever perished?" (Iyov 4:7). At the end, God says to Elifaz and his two friends: "You have not spoken rightly about Me, as My servant Iyov has" (Iyov 42:7). The people who explained Iyov's pain as his fault are the ones God says did not speak rightly.
Notice when the verse is said. It is spoken afterward, by someone who got through it: "but He did not hand me over to death." Radak puts it in the past: these were the days when the speaker was in trouble, and he is looking back.
Radak and Rashi on Tehillim 118:18,Berakhot 5a,Mishlei 3:12,Iyov 4:7 and 42:7