The Talmud tells us that various sages would add a personal supplication after reciting the text of the prayer service. Some of these heartfelt prayers have made their way into our liturgy and have become part of the fixed prayer service. Thus Rav's prayer addendum has become a standard part of the text recited on the Shabbat that precedes Rosh Hodesh (first of a new month) in the Ashkenazi prayer rite. In this prayer we announce the beginning of a new month and pray for blessings in the coming month. As we look to the onset of a new month, the words of Rav's prayer are most appropriate (B. Brachot 16b): May it be Your will, God our Lord, that You give us long life, a life of peace, a life of goodness, a life of blessing, a life of sustenance, a life of physical health, a life in which there is fear of sin, a life in which there is no shame or humiliation, a life of wealth and of honor, a life in which we will have a love of Torah and a fear of heaven, a life in which You will fulfill for us all our heart's desires for good. Beyond the desire to ask for a month blessed with manifold goodness, the passage mentions the term "life" 11 times, corresponding to the 11 times each year when we bless the new month; only before the month of Tishrei, the onset of the new year, do we not pronounce the blessing. When examining this prayer, alas, a number of questions arise. The most obvious issue concerns the text. As with so many prayers, over the ages the wording of the prayer has slightly evolved. Thus what we find in standard prayer books does not exactly match the original text recorded in the Talmud. Notably, in the hassidic tradition at the end of the prayer three words are appended: bizchut tefillat Rav, in the merit of the prayer of Rav. What is the story of this addition? One avenue to understand this addition is by reference to the talmudic passage that comments on a literal reading of the biblical verse "O that I might dwell in Your tent of the worlds" (Psalms 61:5), noting that the psalmist appears to be requesting to live in two worlds simultaneously. The Talmud explains that David turned to the Almighty with a request that Torah should be cited in his name posthumously in this world. Indeed, we have a tradition that when Torah is cited in the name of a deceased scholar, it is as if the lips of the deceased move while the scholar is entombed in the grave. Thus the dead can be said to be alive in two worlds concurrently (B. Yevamot 96b-97a; B. Bechorot 31b). Following this tradition, when we recite this prayer before Rosh Hodesh, the lips of the deceased author of the prayer move. We ask God that our requests should be granted - not in the merit of our own prayer, but in the merit of the prayer of Rav that is being recited by the deceased scholar as we say the prayer. Of course this begs the question: Why do we not evoke the merit of other prayer authors whose lips are presumably reciting the prayers as we offer supplications? Perhaps we should conclude the silent Amida with the words "in the merit of the men of the Great Assembly," the sages who established the text of this central prayer? Another approach prefers a slightly different textual addition: bizchut tefillat rabbim, in the merit of the prayer of the masses. Indeed we do not generally mention individual prayer authors during the service and this prayer should be no exception. We recall, however, the merit of the community as we ask for our requests to be granted. This approach too may be questioned: Wouldn't we want to evoke the merit of communal prayer for all our supplications, not just before Rosh Hodesh? Other authorities advocated against saying these three words not because of their content but due to the suspect history of their inclusion, suggesting that their inclusion was a product of a series of mistakes. According to one approach, the original text did not include these three words, as per the extant talmudic text. At some stage, the source of this prayer was annotated and below the text the words Tefillat Rav were written, indicating that this is the prayer of Rav as it appears in the Talmud. An unknowledgeable copyist or typesetter saw these words and thought they were part of the prayer and so appended them to the text. The words Tefillat Rav have no meaning, and thus another word was added, bizchut, in the merit of. The prayer, however, was still unclear: The merit of which "rav" was being evoked? Thus the words were altered to read bizchut tefillat rabbim, and the merit of the communal prayer was being called forth to justify a month filled with blessing (Rabbi Zvi Elimelech Shapiro of Dynow, 19th century, Galicia; Rabbi Yehiel Mikhel Halevi Epstein, 19th century, Russia). Another author offered a different explanation for the addition of the word bizchut: The original annotation was Brachot Tefillat Rav, meaning that this was the prayer of Rav as found in our talmudic tractate Brachot. Alas, a copyist saw the word brachot and mistook the Hebrew letter resh for a zayin, and copied the word berachot as bizchut (Rabbi Baruch Halevi Epstein, 19th-20th centuries, Russia). Indeed the influence of the copyists, typesetters, printers - the proverbial bochur-a-zetzer, the lad whose was vocation was to set the letters that were to be printed - is astounding, often perplexing and at times troubling. This is hardly the forum for an indictment of the careless bochur-a-zetzer, or perhaps an indictment of those who entrusted him with this important task. Nevertheless this tale reminds us of the importance of meticulous transmission of our tradition, so that our children will not have to grapple with texts that we have negligently corrupted. The writer is on the faculty of Pardes Institute of Jewish Studies and is a rabbi in Tzur Hadassah.