"The first seven letters correspond to “‘Alí-Muḥammad”, and the second seven to “Ḥusayn-Alí”."

 

"Thou hast sought permission for a visit. In these days, the Holy Land is in turmoil by reason of the calumnies spread by the slandering liars. For certain strangers from amongst the non-believers have published some books, filled them with countless calumnies, and distributed them in these regions. ‘Abdu’l-Bahá is therefore in dire peril due to attacks from within and from without. Such are the enemies of the Faith on the outside, and such the violators of the Covenant on the inside. It is thus evident what commotion hath arisen. Yet, praise be to God, through the unfailing grace of the Blessed Beauty, I have remained firm in my position, have bared my breast to the darts of malice hurled by every oppressor, and am awaiting the onslaught of tribulations from every side, that, wholly detached, I may hasten to the shelter of His transcendent mercy.

Thou hast asked about the blessed Quranic verse “We have given thee the twice-repeated seven.”¹¹⁷ The Muslim divines have interpreted the term “twice-repeated seven” to refer either to the seven chapters of the Qur’án that begin with the disconnected letters Ḥá’ and Mím or to the opening chapter of the Qur’án. They say it is “twice repeated” because the opening chapter, consisting of seven verses, was revealed twice—once in Mecca and again in Medina—and, as such, it is twice repeated. Furthermore, they say that as this opening chapter is recited twice in the daily prayer, it is thus described as the “twice-repeated seven”.

But the true meaning is the mystery of Divine Unity and the outpourings of heavenly grace, and that is the glad-tidings of the advent of the subsequent Revelation, in which the Bearer of the seven letters hath appeared twice. The first seven letters correspond to “‘Alí-Muḥammad”, and the second seven to “Ḥusayn-Alí”.¹¹⁸This is the meaning of the “twice-repeated seven”. Yet another meaning is that Muḥammad, the universal Manifestation of the Quranic Dispensation, together with thirteen distinguished souls, make fourteen, which is seven twice repeated.¹¹⁹ There is no time for further elaboration. This is a brief but beneficial explanation."

(Light of the World: Selected Tablets of ‘Abdu’l-Bahá, #68, part 2)
www.bahai.org/r/035253047