Munirih Khanum, wife of ‘Abdu’l-Bahá, who was the Greatest Branch of the Tree of Life had this to say:
Five of my children died in the poisonous climate of ‘Akká. The bad air was, in truth, only the outside material reason. The inner spiritual reason was that no son of the Master should grow into manhood.
When my darling little son Husayn passed away, Bahá’u’lláh wrote the following: “The knowledge of the reason why your sweet baby has been called back is in the mind of God, and will be manifested in His own good time. To the prophets of God the present and the future are as one."
Therefore I understand how that wisdom has ordained the uniting of the two families, that of Bahá’u’lláh and of the Bab, in the person of Shoghi Effendi, eldest son of our daughter, Diyaiyyih Khanum, by her marriage with Aqa Mirza Hadi Afnan.
I have been writing to the friends in Persia; “You are longing to meet us, we are longing to meet you; what is the wisdom in our separation?"
Let us understand that if Bahá’u’lláh had not been exiled to Baghdad, Constantinople, Adrianople, and ‘Akká, the Divine Message could not have been so quickly spread, and the prophecies in the Holy Books would not have been fulfilled.
(Lady Blomfield, The Chosen Highway)