I would like to “call out” Moshe Yedidya Blass, R’ Dan Kaufman, and R’ Shlomo Weiss for answering last Friday’s query. (Names are given in the order in which the answers were received—I also just realized that it is in alphabetical order!)
I have some theories as to why only 3 people responded—I will keep them to myself.
There is near universal Ashkenazic minhag during the month of Elul to recite the Chapter of Tehillim (27) “L’Dovid Hashem Ori” during davening, both every morning and evening, and all the way up to Shmini Atzeres, as preparation for the Yomim Noraim. This custom is based on the Midrash Shochar Tov that elucidates that various phrases of this chapter contain allusions to the holidays of the repentance period – Rosh Hashana, Yom Kippur, and Sukkos, as well as to the month of Elul itself. (the last line of “L’david” contains the word “lulay” which consists of the same letters as the word “Elul” which further alludes to the connection between this chapter of Tehillim and the month of Elul).
The Malbim, in his commentary on Tehillim, offers an alternate explanation. In this chapter, Dovid HaMelech, the author of Tehillim, asked to cleave to Hashem and that all obstacles that block coming close to Him should be removed. The Malbim explains that when we strive to do so, Hashem will attach Himself to us with a higher level of personalized supervision. It is thus quite apropos to recite “L’Dovid” during the month of Elul, whose name hints to the acronym “Ani L’dodi V’dodi Li – I am to my beloved and my beloved is to me” (Shir HaShirim Ch. 6, verse 3). Elul is a month which symbolizes our relationship to Hashem, and one in which proper repentance is more readily accepted.
Another explanation is that this is a time of Divine mercy, as it was when Moses achieved forgiveness for the people after the sin of the Golden Calf. Every year, it is the time when G‑d is especially accessible, like a king who goes out to the field to make Himself available to any subjects who wish to greet him. As seen in the narrative of Moses’ time on high securing forgiveness, a key element of G‑d’s mercy is the phrase known as the “13 Attributes of Mercy.” Appropriately, G‑d’s name (the Tetragrammaton) is mentioned 13 times in this psalm.