The Pesukeh De'zimra section of the prayer service concludes with the blessing of Yishtabah. This section begins with a Beracha – Baruch She'amar – and then concludes with a Beracha, the special Beracha of Yishtabah. One of the things that make Yishtabah so unique is that, according to tradition, it was composed by Abraham Abinu, whose name is alluded to in the text of this Beracha. Toward the end of Yishtabah, we read the words "Kel Ha'hoda'ot Adon Ha'nifla'aot Boreh Kol Ha'neshamot Ribon Kol Ha'ma'asim Ha'boher Be'shireh Zimra Melech…" The first letters of the words "Kel," "Adon," Boreh," "Ribon," "Ha'boher" and "Melech" spell the name "Abraham." Rav Haim Vital (1543-1620) taught that the beginning of Yishtabah was composed by King Shlomo, whose name is alluded to in the first line of this blessing. The first letters of the words "Shimcha," "La'ad," "Malkenu." "Ha'kel" spell "Shelomo." In this blessing, we list thirteen different expressions of praise for Hashem: "Shir," "Shebaha," "Hallel," "Zimra," "Oz," "Memshala," "Nesah," "Gedula," "Gebura," "Tehila, "Tiferet," "Kedusha" and "Malchut." The Ben Ish Hai (Rav Yosef Haim of Baghdad, 1833-1909) taught that these thirteen expressions correspond to G-d's thirteen attributes of mercy. He further wrote that it is proper to count these thirteen words on one's fingers, adding that he himself followed this practice. Ashkenazim have the custom to stand during the recitation of Yishtabah, though the practice among Sepharadim is to remain seated. There were some communities that would add various songs and hymns before Yishtabah, after the recitation of Az Yashir. However, according to the teachings of the Arizal and his disciple, Rav Haim Vital, this practice is incorrect, as no interruption should be made in between Az Yashir and Yishtabah.