BibTeX:
@incollection{Various,
  author = {Various},
  title = {The old man and the king – a story told by ‘Abdu’l-Baha},
  booktitle = {Baha'i Stories for Children},
  url = {https://bahaistoriesforchildren.blogspot.com/2022/03/the-old-man-and-king-story-told-by.html},
}

APA:
Various. The old man and the king – a story told by ‘Abdu’l-Baha. In *Baha'i Stories for Children*.

MLA:
Various. "The old man and the king – a story told by ‘Abdu’l-Baha." *Baha'i Stories for Children*, n.d..

Chicago:
Various. "The old man and the king – a story told by ‘Abdu’l-Baha." In *Baha'i Stories for Children*, n.d..