The Ben Ish Hai (Rav Yosef Haim of Baghdad, 1833-1909) discusses the importance of reciting "Hodu Le’Hashem Kir’u Bi’shmo" and the subsequent series of verses before the Shaharit service (listen to audio recording for precise citation). He writes that it is proper to recite these verses immediately after concluding the "Tamid" and "Ezehu Mekoman" sections of the service, which discuss the sacrifices. During the morning Tamid offering in the Temple, the Leviyim in the Mikdash would sing the verses from "Hodu" through "U’bi’nbi’ai Al Tare’u," and during the afternoon Tamid offering, they would sing from "Shiru L’Hashem" through "Ve’hallel L’Hashem." It is therefore appropriate to recite these verses immediately following the section of the prayer service that deals with the sacrifices offered in the Bet Ha’mikdash. The Ben Ish Hai notes that this was the practice of the Arizal (Rav Yishak Luria of Safed, 1534-1572), as recorded in the Sefer Ha’kavanot. This is in contrast to the custom of the Ashkenazim, who recite "Hodu" after Baruch She’amar.
Furthermore, the Ben Ish Hai adds, according to Sod (Kabbalistic thought), there is great significance to the recitation of the verses of "Hodu" before the main prayer service. This recitation helps to eliminate the "Kelipot" – the spiritual forces that could potentially interfere with our prayers and prevent them from reaching their destination in the heavens. It is therefore essential to recite the verses of "Hodu" before the main section of the prayer service, as printed in the Siddurim.
The Ben Ish Hai writes that if a person, for whatever reason, is unable to come to the synagogue for the beginning of the prayer service, and therefore recites at home the first part of the service, from the Akeda until "Hashem Melech," he should repeat "Hodu" when he arrives in the synagogue. "Hodu" should be recited shortly before the recitation of Ashreh and the subsequent chapters of Tehillim that are recited as part of Pesukeh De’zimra. (This is why the Ashkenazim recite "Hodu" after Baruch She’amar.) Therefore, if a person recited the first section of the prayer service at home, he should repeat "Hodu" when he arrives in the synagogue before he proceeds with Baruch She’amar and the rest of the Pesukeh De’zimra.
Finally, the Ben Ish Hai writes that when we recite the verse of "Hodu L’Hashem Ki Tob Ki Le’olam Hasdo" in the "Hodu" section, we do not repeat this verse. Even though we repeat this verse when we recite it in Hallel, it is not repeated in the daily recitation of "Hodu."
Summary: It is important to recite the verses of "Hodu" each morning before the main part of the prayer service. Sephardic practice is to recite this series of verses after "Ezehu Mekoman." If one had recited at home the first part of the prayer service, from the Akeda through "Hashem Melech," and then comes to the synagogue for the rest of the service, he should repeat "Hodu" before proceeding with Baruch She’amar.
