137. the Most Great Name [#109]
As explained in note 33, the Greatest Name of God can take various forms, all based on the word "Bahá". The Bahá’ís in the East have implemented this injunction of the Aqdas by heading their wills with such phrases as "O Thou Glory of the All-Glorious", "In the name of God, the All-Glorious" or "He is the All-Glorious" and the like.
138. All Feasts have attained their consummation in the two Most Great Festivals, and in the two other Festivals that fall on the twin days [#110]
This passage establishes four great festivals of the Bahá’í year. The two designated by Bahá’u’lláh as "the two Most Great Festivals" are, first, the Festival of Ridván, which commemorates Bahá’u’lláh’s Declaration of His Prophetic Mission in the Garden of Ridván in Bag̱ẖdád during twelve days in April/May 1863 and is referred to by Him as "the King of Festivals" and, second, the Báb’s Declaration, which occurred in May 1844 in S̱ẖíráz. The first, ninth and twelfth days of the Festival of Ridván are Holy Days (Q and A 1), as is the day of the Declaration of the Báb.
The "two other Festivals" are the anniversaries of the births of Bahá’u’lláh and the Báb. In the Muslim lunar calendar these fall on consecutive days, the birth of Bahá’u’lláh on the second day of the month of Muharram 1233 A.H. (12 November 1817), and the birth of the Báb on the first day of the same month 1235 A.H. (20 October 1819), respectively. They are thus referred to as the "Twin Birthdays" and Bahá’u’lláh states that these two days are accounted as one in the sight of God (Q and A 2). He states that, should they fall within the month of fasting, the command to fast shall not apply on those days (Q and A 36). Given that the Bahá’í calendar (see notes 26 and 147) is a solar calendar, it remains for the Universal House of Justice to determine whether the Twin Holy Birthdays are to be celebrated on a solar or lunar basis.
139. the first day of the month of Bahá [#111]
In the Bahá’í calendar the first month of the year and the first day of each month are given the name "Bahá". The day of Bahá of the month of Bahá is thus the Bahá’í New Year, Naw-Rúz, which was ordained by the Báb as a festival and is here confirmed by Bahá’u’lláh (see notes 26 and 147).