It was only two weeks ago that thousands journeyed to Meron to commemorate the anniversary of the death of famed Rabbi Shimon bar Yohai, the great sage of the Mishna and hero of the Zohar. As per tradition, the central bonfire on the roof of the grave was lit by the Boyaner Rebbe, Rabbi Nachum Dov Brayer – a privilege he inherited from his ancestors.Meron on Lag Ba’omer is a unique experience. For sheer size it is unparalleled: by far, it is the largest annual gathering in Israel. Festivities are not confined to the graveside nor to Meron, and not even to the Galilee. All over Israel, bonfires are lit, boys have their first haircut, and people join in song. The day is commemorated across the spectrum, though it would appear that hassidim and Sephardim are the most committed celebrants.There are three songs that might be considered the soundtrack of Meron on Lag Ba’omer, one of which has an enigmatic history. The first song features the words of Rabbi Akiva as recorded in the Mishna at the end of tractate Yoma (8:9): “Fortunate are you, O Israel, before whom you purify yourselves and who purifies you – your Father in Heaven!” Moreover, it also says, ‘O You, God, hope of Israel [mikve Yisrael]’ (Jeremiah 17:12) – just as a mikve purifies the impure, so too the Holy One blessed be He purifies Israel.”Rabbi Akiva was the teacher of Rabbi Shimon bar Yohai, but perhaps more pointedly his students ceased dying from a plague on Lag Ba’omer. Hence his words have become part of the soundscape of Lag Ba’omer in Meron.The second song – “Bar Yohai” – is a 10-stanza poem laden with kabbalistic allusions. As indicated yb the acrostic poem, it was penned by the 16th century kabbalist Rabbi Shimon Ibn Lavi, a native of Spain whose family found haven in Morocco following the expulsion. In 1551, Ibn Lavi set out for the Land of Israel, but when he reached Tripoli in Libya he decided to stay and serve as rabbi. In addition to “Bar Yohai,” he penned a commentary on the Zohar titled Ketem Paz. A portion of Ketem Paz was first printed in Venice in 1658, but it was only in Livorno in 1795 – more than two centuries after Ibn Lavi’s death – that the entire work was published.The third Lag Ba’omer song is “Va’amartem ko lehai” – a beautiful 22-stanza rhyming poem about Rabbi Shimon Bar Yohai, with the refrain “Adoneinu Bar Yohai” – our master the son of Yohai. Who is the author of this poem that is sung with such gusto by hassidim at Meron? In the case of “Va’amartem ko lehai” the acrostic follows the letters of the Hebrew alphabet, so the identity of the author is not readily apparent.In 1877, a slender book titled Hilula Raba – the great celebration – was published in Livorno including various poems and readings in honor of Rabbi Shimon bar Yohai and Lag Ba’omer. At first blush, the 1877 Livorno Hilula Raba is not much more than a bibliographic footnote: Hilula Raba booklets had already been printed in Livorno (in 1819, 1829, 1847 and 1860), and a similar work had also been printed in Lemberg in 1863. Indeed, after the 1877 Livorno edition, Hilula Raba booklets would continue to appear during the 19th century in Livorno (in 1881 and 1882) and in Jerusalem (in 1884 and 1891), with more editions appearing in the 20th century. Thus works entitled Hilula Raba seemed to be quite popular beginning in the 19th century.What makes the 1877 edition stand out is that it includes the poem “Va’amartem ko lehai.” Alas, no indication of the author nor of the provenance of the poem is offered.In 1904, a tiny book titled Rina Vetefila was printed in Jerusalem. In their introduction, the editors explained that they included a variety of prayers “according to the custom of our brothers in the land of Bukhara.” They did not mention that they also included “Va’amartem ko lehai.” It is described as a “nice poem, an acrostic in honor of the holy scholar Rabbi Shimon bar Yohai, may his merit protect us.” The poet’s identity was still not revealed.In that same year, the famed Baghdadi scholar Rabbi Yosef Haim (1834- 1909) – more commonly known as Ben Ish Hai – published a work entitled Lashon Hachamim, the language of the wise. In this work Rabbi Yosef Haim mentioned that he was the person behind the 1877 Hilula Raba! At this point the identity of the editor became apparent: It was Rabbi Yosef Haim who had decided what to include and had a hand in shepherding the printing process through its various stages. But where did he get the mysterious “Va’amartem ko lehai” poem? The National Library of Israel holds an undated manuscript of a Passover Haggada that follows the Baghdadi rite. The manuscript includes “Va’amartem ko lehai” and attributes the poem to Rabbi Yosef Haim himself! Thus far this is the earliest attribution of the poem that I have found. The manuscript is difficult to date, though apparently it was penned at the beginning of the 20th century. Furthermore, it is difficult to ascertain how widely the author’s identity was known, based on a private manuscript.Zooming in on one stanza of the poem – “Sinai, Sinai, he is called; the lion of the pride from whom Torah comes out; our master, the son of Yohai” – identifies Shimon bar Yohai with the mountain where the Torah was given, which might seem presumptuous. But as hassidim of Eastern European extract lock arms and dance energetically to a poem written by a Baghdadi scholar, we are reminded that at Sinai – in some ways like Meron today – we all stood together. ■ The writer, a rabbi in Tzur Hadassah, is on the Pardes faculty and a post-doctoral fellow at Ben-Gurion University of the Negev.