BibTeX:
@incollection{Various,
  author = {Various},
  title = {Once, when I lived in Baghdad," He [‘Abdu’l-Bahá] went on, "I was},
  booktitle = {bahaistories.com archive},
  url = {https://bahaistories.com/subject/guest},
}

APA:
Various. Once, when I lived in Baghdad," He [‘Abdu’l-Bahá] went on, "I was. In *bahaistories.com archive*.

MLA:
Various. "Once, when I lived in Baghdad," He [‘Abdu’l-Bahá] went on, "I was." *bahaistories.com archive*, n.d..

Chicago:
Various. "Once, when I lived in Baghdad," He [‘Abdu’l-Bahá] went on, "I was." In *bahaistories.com archive*, n.d..