BibTeX:
@incollection{Bahullh2002,
  author = {Bahá'u'lláh},
  title = {In a State of Utmost Joy},
  booktitle = {The Summons of the Lord of Hosts},
  year = {2002},
}

APA:
Bahá'u'lláh. (2002). In a State of Utmost Joy. In *The Summons of the Lord of Hosts*.

MLA:
Bahá'u'lláh. "In a State of Utmost Joy." *The Summons of the Lord of Hosts*, 2002.

Chicago:
Bahá'u'lláh. "In a State of Utmost Joy." In *The Summons of the Lord of Hosts*, 2002.