On Shabbat morning, before Baruch She'amar, we recite a series of chapters from Tehillim, starting with "La'menase'ah Mizmor Le'David" – the 19 th chapter of Tehillim. Among the unique features of this chapter is a series of three verses (8-10) that all have the identical structure. Each of these verses consists of two halves, each of which contains five letters, and the second letter is the Name "Havaya." The first verse in this series begins with the five words "Torat Hashem Temima Meshibat Nafesh," and concludes with the five words "Edut Hashem Ne'emana Mahkimat Peti." The next two verses follow the same format – consisting of two five-word clauses, where the second word of each clause is "Hashem." The Ben Ish Hai (Rav Yosef Haim of Baghdad, 1833-1909) writes that when one recites these verses, he should count every series of five words with his five fingers, starting with his thumb, such that Hashem's Name will always be counted with his index finger. This finger is associated with the divine Name of "Havaya," and so it is extended when this Name is read. Furthermore, the Ben Ish Hai adds, whenever a person finds himself under attack, he should recite these verses in this manner – counting each series of five words with his fingers. And each time he extends his index finger to count Hashem's Name, he should point it at the person who threatens him, and this will protect him from the threat. Interestingly enough, the Ben Ish Hai writes that the six-pointed star known to us as the "Magen David" – "David's Shield" – corresponds to the six instances of Hashem's Name in these verses – twice in each of the three verses. King David's shield was shaped this way because the Name of "Havaya" in these verses protected him from his enemies during battle. The Ben Ish Hai explains on this basis the verse in the Book of Debarim (21:10) which speaks of Hashem giving our enemies into "our hands" ("U'netano Hashem Elokecha Be'yadecha"). The soldiers would use these verses when going out to war, reciting them and counting with their fingers, and in this sense, the enemies were delivered into their "hands," through the soldiers' counting with their fingers. Additionally, the Ben Ish Hai writes, this is why the groom customarily places the ring specifically on the bride's index finger. The Shechina resides among a married couple, and so the bride extends this finger, which is associated with the Name of "Havaya," to show that she and the groom are now connecting with the Shechina as they set out to build their home.