According to Readers Guide to The Mahatma Letters to A. P. Sinnett:
Benjamin, one of the nicknames for Djual Khul. Apparently it derives from the Bible story of the disinherited brother of that name. he was frequently called "the Disinherited" due to the fact that he had been disinherited by his family when he became interested in occultism.
- George E. Linton and Virginia Hanson, eds., Readers Guide to The Mahatma Letters to A. P. Sinnett (Adyar, Chennai, India: Theosophical Publishing House, 1972), 219.