(Delivered in Hebrew by Rav Bitton, author of Yalkut Yosef)
I.
Twice in the morning Shaharit prayer we recite the Pasuk, "Ve’shahat Oto Al Yerech Ha’mizbe’ah Safona Lifneh Hashem." (This verse speaks of the slaughtering of the Ola sacrifice and the sprinkling of its blood.) We recite this Pasuk immediately after the Akeda section, and then again later, just before "Ezehu Mekoman." The Tur (Rabbenu Yaakob Ben Asher, 1269-1343), however, in Siman 48, mentions only the recitation of this verse before "Ezehu Mekoman," where it is recited because it relates to the Tamid sacrifice which we mention earlier. (This Pasuk is recited only at this point because the section of the Ketoret must be recited immediately after the portion about the Tamid.) But the Tur makes no mention of reciting this verse after the Akeda, and in fact this practice does not appear in any early source. It was mentioned by the Hida (Rav Haim Yosef David Azulai, 1724-1807), in his work Kesher Gudal (24), where he cites the Midrash’s comment that this verse alludes to Yitzhak, who was placed upon the altar and nearly slaughtered. The Midrash says that G-d considers Yishak as though he was actually sacrificed, and has his ashes in front of Him at all times as a source of merit for the Jewish people. Since this verse relates to the Akeda, the Hida writes, it is proper to recite it immediately after the section of the Akeda.
The Kaf Ha’haim (Rav Yaakob Haim Sofer, Baghdad-Israel, 1870-1939), however, disapproves of this practice. He writes (1:30) that it is forbidden to recite any verses related to sacrifices before reciting the section of the Tamid, and thus the verse, "Ve’shahat Oto" should not be recited after the Akeda. The Kaf Ha’haim adds that the custom in Yeshivat Bet-El and among all those who followed the teachings of the Arizal (Rav Yishak Luria of Safed, 1534-1572) was not to recite this verse after the Akeda, and to recite it only later, before "Ezehu Mekoman." Nevertheless, the Ben Ish Hai (Rav Yosef Haim of Baghdad, 1833-1909) followed the Hida’s view and maintained that one should recite this verse after the Akeda, and this is, indeed, the widespread practice, as indicated in all the Siddurim.
II.
In Siman 2, the Shulhan Aruch writes, "It is forbidden to walk with one’s head held up high, and one should not walk four Amot with his head uncovered." Hacham Ovadia observed that when it comes to Koma Zekufa (walking with one’s head held up high), the Shulhan Aruch uses the word "Assur" ("it is forbidden"), indicating that this is a strict prohibition, but regarding walking with one’s head uncovered, he writes simply, "one should not." It appears, the Hacham noted, that walking with one’s head uncovered is not forbidden on the level of strict Halacha, but rather as a Middat Hasidut (measure of extra piety), as the Hida maintained. The Hida noted that the Gemara records the remark of one of the Sages, "I am deserving [‘Teiti Li’] because I do not walk four Amot with my head uncovered," and this expression is generally used in reference to special measures of piety, and not to strict Halachic requirements.
However, in his work Yabia Omer (vol. 8), Hacham Ovadia writes that even holding one’s head up high is forbidden only on the level of "Middat Hasidut," and not as a strict Halacha. It seems that in his conclusion, Hacham Ovadia did not find any significance in the distinction between the different formulations used here by Maran ("Assur" and "En Lelech"). Indeed, the Ma’amar Mordechai writes in several contexts that Maran occasionally changes his formulation "Le’tif’eret Ha’lashon" – in the interest of eloquence, and we thus cannot draw any Halachic conclusions from these variant formulations.
As for the requirement of covering one’s head, several authorities, including the Petah Ha’dbir and Rav Shalom Mesas, maintained that this is required on the level of strict Halacha. Hacham Ovadia Yosef, as noted, disagreed, and held that this requirement applies only as a "Middat Hasidut." Nevertheless, he adds that since nowadays wearing a Kippa has become an important symbol of identification with the Jewish people and with Torah observance, it should certainly be treated as a strict requirement.
There is a debate among the Poskim as to the minimize size of the Kippa. The Hazon Ish (Rav Abraham Yeshaya Karelitz, 1878-1953) maintained that the Kippa must cover the majority of one’s head, whereas Rav Moshe Feinstein (1895-1986) maintains that it suffices for the Kippa to be visible from all directions, even if it does not cover most of the head. Rav Moshe draws proof from the Shulhan Aruch’s ruling (91) that if one’s head is covered by somebody else’s hand, this suffices as a covering and the person may pray the Amida with his head covered in this fashion. It is highly unlikely, Rav Moshe notes, that a person’s hand is capable of covering the majority of someone’s head, and we may thus conclude that a Kippa does not have to cover the majority of the head. Rav Chaim Kanievsky (contemporary) suggested refuting this proof by noting that the Shulhan Aruch perhaps requires placing both hands on the person’s head, or speaks of an adult placing his hand on the head of a youngster. Although this does not appear to be the Shulhan Aruch’s intent, the Hazon Ish, as mentioned, maintained that one’s Kippa must cover the majority of his head, and it is certainly proper to follow this view, particularly in light of the important role that the Kippa plays in fostering a sense of religious identity.