We are told by the beloved Guardian that the Epistle to the Son of the Wolf is "the last outstanding Tablet revealed by the Pen of Bahá'u'lláh."- (Shoghi Effendi, ‘God Passes By’)
Shoghi Effendi gave the western believers his fifth and last book of translations of the Writings of Bahá'u'lláh, undertaken during the winter of 1939-40 … ‘The Epistle to the Son of the Wolf’ was Bahá'u'lláh's last major work and contains a selection from His own Writings made by Himself (surely a unique occurrence in religious history!) during the last two years of His life and has therefore a special position of its own in the literature of our Faith. In a cable shortly prior to its publication Shoghi Effendi said "Devoutly hope its study may contribute further enlightenment deeper understanding verities on which effective prosecution teaching administrative undertakings ultimately depend..."
- Ruhiyyih Khanum (‘The Priceless Pearl’)