A fairly universal custom is to recite the passage from Psalms l'Dovid Hashem Ori twice a day during the month of Elul. A question which has received renewed scrutiny recently is where this custom came from. The most obvious answer is the work Hemdat Yamim. This work, however, is rather controversial. Many claim this book (which has many other well-accepted customs) was written by Nathan of Gaza, the prophet of the infamous false-Messiah Shabbetai Zevi. Thus, if the Hemdat Yamim is in fact the source, that would not be a good thing.

So, some have claimed that in fact there is another source for the recitation of l'Dovid HaShem during Elul. They point to the book Shem Tov Kotton. In this book, which is a collection of additionally kabbalistic prayers, there is a mention to say l'Dovid HaShem during Elul. The problem, however, is that a) Shem Tov Kotton only says to do so on Monday and Thursday and the 10 days of repentance but not everyday in Elul; (b) he also says that not only one should say l'Dovid but also additionally prayers some of his own compilation and others such as the 13 middot haRachmim and the Psalm Rananu Tzadikim; (c) finally, he says to say l'dovid HaShem immediately after Shmonei Esreh. So it would seem that in all likelyhood the Shem Tov Katton is not the source of our custom to say l'Dovid daily, at the end of prayers, without any additional prayers.[1]

So we are back to square one. Lest one despair some have come to fill this gap. They say anyways the Shem Tov Koton would not have been the best source as they would rather this custom ultimately come from the Ari'zal (which the Shem Tov Koton would not). Now, some just claim the Hemdat Yamim is really a student of the Ari and is perfectly kosher. This solves everything, but that is not the general consensus. Instead, they have located that R. Hayyim haKohen who was known as student of the R. Hayyim Vital and himself an important conduit for the Ari'zal's writtings, says to say l'Dovid HaShem during Elul. Now, as it was we have a Ari'zal source so the custom has been saved.

Not so fast. First, a rather interesting work was recently redone and republished on the Shir Shel Yom. This book, Shirei haLevim, is everything and anything having to do with the Shir Shel Yom. The book, discusses all the Ari"zal's customs as connected to the Shir Shel Yom, the book was originally published in 1677. However, no where in this book is there any discussion of l'Dovid, which tends to show that although the author was well versed in all the other Ari'zal's Shir Shel Yom customs, it seems not this one. Thus, it seems doubtful this custom actually emerged from the Ari'zal.

But, even more questionable is that in the manuscript from which R. Hayyim Kohen's comments were published that manuscript contains nothing about l'Dovid haShem instead, it appears the publisher inserted into the R. Hayyim's work. And as already has noted by some (see Yudolov's comments for the entry of Sha'arei Rachmim [No. 0182652] on the Bibliography of the Hebrew Book 1470-1960) many insertations to the work in question, the Sha'arei Rotzon, are found in the Hemdat Yamim.

2007 Update: Also, it is worth pointing out the lengths persons will go to obscure the Hemdat Yamim source. For instance, in the Siddur Alyiyat Eliyahu and the Machzor by the same editor, Mikrai Kodesh, in both these siddurim the editor offers the following as the source for l'Dovid: "Sha'arei Tefilah which attributes this custom to R. Hayyim Kohen, a student of the AriZa"L, Shem Tov Koton." So, the earliest source is this work Sha'arei Tefilah which attributes it tho R. Hayyim Kohen - this apparently is a new source, which, although we have seen other sources which attribute it to R. Hayyim we saw that source was questionable at best. While the editor did not explain which of the many Sha'arei Tefilah he is referring to[2], in fact he is referring to R. Ya'akov Raccah's work published in 1870. Now, as this work is published in 1870 and supposedly is the source for what R. Hayyim Kohen who died in 1655 and authored many of his own works which discuss similar topics should immediately be a red flag . When one actually looks at the Sha'arei Teffilah the quote (p. 48) one sees that he is not the source, instead, all the Sha'arei Teffilah does is quote the Sha'arei Rotzon, which, as noted above, we now know is not actually a quote from R. Hayyim, and instead merely the later insertation of the editors of that work. Now, why would the editor go so far out of his way to reference a rather obscure work from the late 19th century as the first source for this custom but never make any mention of the earlier source Hemdat Yamim at all? It would seem that he wanted to avoid as much as possible any connection to this source.

Notes:
[1] R. Katz, in Divrei Yosef (p. 175) uses the differences between the custom advocated for the Hemdat Yamim - l'dovid should be recited prior to selichot, as a "proof" that our custom can not be based upon Hemdat Yamim. Katz, however, is silent about the numerous differences between our custom and what the Shem Tov Koton advocates for.

[2] It is especially ironic that the editor did not explain which Sha'arei Tefilah he is referencing as the editor spends a considerable portion of his introduction castigating R. Shlomo Zalman Hanau's Sha'arei Tefilah (the most well-known work with the title Sha'arei Teffilah) for numerous precieved sins. Such a bland citation my lead an innocent reader to make the grave error that the editor is now citing to this "horrible" work.

Sources: Shirei HaLevim was reprinted and retypeset in the book Shirat Shmuel; on l'Dovid see Ohr Yisrael no. 1 by R. Katz (reprinted in his Divrei Yosef); Shem Tov Koton, Chernowitz, 1855 12a-13a (available online at Hebrewbooks.org; R. Goldhaber, Minhagei Kehillot vol. 2 p. 8 (he is the source for the manuscript evidence) Goldhaber's work is generally excellent; on Hemdat Yamim (the recent controversy) see R. M. Tzuriel's recent reprint and his introduction; R. N. Greenwald "The Attitudes of the Leaders of Hassidim towards the book 'Hemdat Yamim'," Hechal HaBesht no. 6; 34-64; R. Mondshien's response in the next issue of Hechal HaBesht and Greenwald's response to R. Mondshein in that issue; for even more on Hemdat Yamim as well as where you can get your own copy for free see my prior post here ; for more on R. Hayyim Kohen, see here about half way down the page.