Why say a psalm about enemies and war in the month before Rosh Hashanah?
On its surface this psalm is about danger: people trying to destroy David, an army camped against him, liars testifying against him. Radak reads it that way, as David's own enemies and his own wars. It is not an obvious fit for the weeks before the High Holidays.
The Midrash (the Rabbis' collections of teachings on the Tanach) makes the fit. In Vayikra Rabbah, one of those collections, the Rabbis read the first verse as a calendar: "Hashem is my light" is Rosh Hashanah, and "my rescue" is Yom Kippur. The Kitzur Shulchan Aruch (a short code of Jewish law from 1864) gives this as the reason for the custom, and adds that "He will hide me in His shelter" hints at Sukkot.
Then the enemies change. In the same Midrash, the ones who come "to devour my flesh" are the angels in charge of the other nations, who argue before God that Israel is no better than anyone else.
It adds a number. The Hebrew for "the accuser," ha-satan, adds up to 364, and the year has 365 days. All year the accuser may speak. On Yom Kippur he may not. The Midrash even ties "in this I trust" in verse 3 to the Torah's Yom Kippur service, in a verse that says "With this Aaron shall enter the Sanctuary."
Read this way, the opening is said by someone about to be judged who is not afraid. That is the Rabbis' second layer of meaning, not the plain one.
Vayikra Rabbah 21:4,Kitzur Shulchan Aruch 128:2,Radak on Tehillim 27:3,Vayikra 16:3David says he is not afraid, then begs God not to leave him. Which is it?
Both, and the psalm is built that way. Verses 1 to 6 are confident: "Whom should I fear?" From verse 7 the tone changes: "Hear my voice," "Do not hide Your face from me," "Do not abandon me."
Radak does not treat this as a contradiction. He says David trusted God to save him from every trouble, and still had one thing to ask for. When verse 7 says "Hear my voice," Radak says this is that same request. Trusting and asking go together.
Then comes verse 13, "Had I not believed..." In the traditional Hebrew text, dots are written above the first word. The Gemara (the main record of the Rabbis' discussions, about 1,500 years old) asks why, and quotes an answer in the name of a sage called Rabbi Yosei. David is saying: I am sure You reward the righteous in the World to Come, but I do not know if I have a share among them. The Gemara explains the worry: maybe a sin would cost him that share. Rashi and Radak both repeat this teaching.
So the dots mark a doubt inside the confidence, and the Rabbis noticed it.
The last verse is advice, and Radak says David is speaking to himself: "Hope in Hashem. Be strong, and He will strengthen your heart. And hope in Hashem." The Gemara uses it as the proof that prayer needs strengthening, and that a person who prayed and was not answered should pray again.
In these sources, doubt and trust sit in the same person. And when a prayer seems unanswered, the advice is to try again.
Radak on Tehillim 27:4, 27:7, 27:13, 27:14,Berakhot 4a,Rashi on Tehillim 27:13,Berakhot 32bThe psalm says "my father and mother left me." What if mine did not?
The verse is blunt: "My father and my mother have left me, but Hashem will gather me in." Many people saying it have parents who are still around. So what is it doing in a prayer for everyone?
The commentators do not agree on what it means, and none of them needs a bad parent. Ibn Ezra says the parents who brought David into the world left him by dying, and God took care of him ever since. He adds that the Hebrew could also mean "will leave me," some day. Radak says that after David left his parents' land, God was the one who provided what he needed.
Rashi's reading is about every parent. It comes from a teaching in Vayikra Rabbah, where David says to God: did my father Yishai (Jesse) have me in mind? When parents bring a child into the world they are thinking of their own enjoyment, not of this particular child. Once that moment is over, each one turns away. God is the one who guards the beginning of a life and forms the baby.
That makes three readings: a loss, a move away from home, and the part of your life that no parent controls.
Radak then connects it to the next verse. Since God has looked after David until now, David asks: "Teach me Your way." The verse is not saying parents do not matter. It is giving a reason to ask for guidance.
Ibn Ezra on Tehillim 27:10,Radak on Tehillim 27:10,Rashi on Tehillim 27:10,Vayikra Rabbah 14:5