BibTeX:
@incollection{Various,
  author = {Various},
  title = {On one occasion ‘Abdu’l-Bahá told about a happy day in Iraq: ‘Once},
  booktitle = {bahaistories.com archive},
  url = {https://bahaistories.com/subject/gratitude},
}

APA:
Various. On one occasion ‘Abdu’l-Bahá told about a happy day in Iraq: ‘Once. In *bahaistories.com archive*.

MLA:
Various. "On one occasion ‘Abdu’l-Bahá told about a happy day in Iraq: ‘Once." *bahaistories.com archive*, n.d..

Chicago:
Various. "On one occasion ‘Abdu’l-Bahá told about a happy day in Iraq: ‘Once." In *bahaistories.com archive*, n.d..