The proclamation "Hashem Melech, Hashem Malach, Hashem Yimloch Le'olam Va'ed," which we make each morning before Baruch She'amar, should be made while standing. On weekdays, "Hashem Melech" is recited just before Baruch She'amar, and so one remains standing until after Baruch She'amar. On Shabbat and holidays, however, when other chapters of Tehillim are recited in between "Hashem Melech" and Baruch She'amar, one must remain standing until he completes the verse recited right after "Hashem Melech" – "Ve'haya Hashem La'Melech…U'Shmo Ehad." The next paragraph – "Hoshi'enu" – may be recited sitting. If one has already prayed Shaharit, and, while learning Torah in the synagogue, he hears the congregation recite "Hashem Melech," then he must stand. Preferably, he should also join them in the recitation. If, however, one hears an individual reciting "Hashem Melech," not with a Minyan, he has no obligation to stand. If a person is praying with a Minyan, and he is still reciting Hodu when the congregation reaches "Hashem Melech," then he should stand but not join the congregation in reciting "Hashem Melech." The Arizal taught that the sequence of the prayer service is vitally important, and so following the proper order takes precedence over the value of joining the congregation in reciting "Hashem Melech." Disrupting the sequence of the Tefila could adversely affect its impact, and so one should not recite "Hashem Melech" early, while he has yet to complete Hodu or the earlier parts of the service. This is the ruling of the Ben Ish Hai (Rav Yosef Haim of Baghdad, 1833-1909) and the Kaf Ha'haim (Rav Yaakob Haim Sofer, Baghdad-Jerusalem, 1870-1939). This is in contrast to the view of the Peri Hadash (Rav Hizkiya Da Silva, 1659-1698), who felt that since we do not pray with all the deep intentions of the Arizal, the sequence of the prayers is not as critical, and thus one should interrupt an earlier part of the service for the sake of joining the recitation of "Hashem Melech." The Ben Ish Hai countered that we should follow the Arizal's practices despite not having all his deep Kavanot (intentions), and so the sequence must be maintained. It is worth noting that if Halacha discourages disrupting the Tefila with the recitation of a different part of the service, then certainly, and many times more so, it forbids interruptions such as reading text messages, checking notifications, and doing other things with one's device. Throughout the entire prayer service, we should try to remain as singularly focused on our Tefila as possible, and make a point of avoiding all distractions. "Hashem Melech" is recited also during the Selihot prayers, and the Ben Ish Hai writes that the aforementioned Halachot apply also when one hears the congregation recite "Hashem Melech" during Selihot, and he is required to stand. Standing during "Hashem Melech" is the accepted custom, but not a strict Halachic requirement. Therefore, an elderly or infirm individual, who finds it difficult to stand, may remain seated for the recitation of "Hashem Melech." The Ben Ish Hai writes that standing is not required during the traditional recitation of "Hashem Melech" during the Hakafot on Simhat Torah. This custom is a relatively new development, and may thus be treated more leniently, such that standing is not required. Hacham Ovadia Yosef raises the question of how the Ben Ish Hai could write this, as standing is strictly required during Hakafot for an entirely different reason – because the Torah scrolls are being carried. Irrespective of the recitation of "Hashem Melech," standing is required in the synagogue when the Sefer Torah is being carried, which is of course happening during Hakafot. Some answer this question by suggesting that the Ben Ish Hai accepted the novel ruling of Rav Shlomo Zalman Auerbach (Jerusalem, 1910-1995) permitting one to sit during Hakafot. Rav Shlomo Zalman asserted that during Hakafot, the Torah scrolls are considered to be in their place, as they are meant to be danced with at this time. Standing for the Sefer Torah is required only when it is removed from its place, and therefore one may sit during Hakafot, when the Torah scrolls are, in a sense, in their place. For this reason, perhaps, the Ben Ish Hai permitted sitting while reciting "Hashem Melech" during the Hakafot. It is unlikely, however, that the Ben Ish Hai followed this novel position, and in fact, it is not accepted as Halacha. The story is told of Hacham Ezra Attieh (1885-1970), Rosh Yeshiva of Yeshivat Porat Yosef, who, as an older man, felt weary during Hakafot on Simhat Torah, and so he left the room to sit down somewhere else. This is the generally accepted Halacha – that even those who feel weak or weary during Hakafot should leave the synagogue to sit. (It should be noted, however, that Hacham Ovadia permitted sitting when the Torah scrolls are stationary in the few moments between Hakafot.) It is more likely, then, that the Ben Ish Hai referred to the practice observed in many congregations to place the Torah scrolls on the Teba after dancing and recite the hymns, including "Hashem Melech," and he therefore wrote that sitting is permissible during that time. Summary: One must stand for the recitation of "Hashem Melech" during Shaharit. If one had already prayed, and, while learning in the synagogue, he hears the congregation recite "Hashem Melech," he should stand and join their recitation. If one is reciting a different part of the prayer service, such as Hodu, then he should rise but not interrupt to recite "Hashem Melech." This applies also to the recitation of "Hashem Melech" during Selihot. Standing is not required, however, for the recitation of "Hashem Melech" during Hakafot if the Torah scrolls are on the Teba and not being carried at that time. The elderly, infirm and others who find it difficult to stand may remain seated for the recitation of "Hashem Melech," even during Shaharit and Selihot.