BibTeX:
@incollection{theBb,
  author = {the Báb},
  title = {After Each Prayer: The Báb on Remembering Parents},
  booktitle = {Selections from the Writings of the Báb},
  publisher = {Bahá'í World Centre},
  url = {https://www.gutenberg.org/ebooks/18828},
}

APA:
the Báb. After Each Prayer: The Báb on Remembering Parents. In *Selections from the Writings of the Báb*. Bahá'í World Centre.

MLA:
the Báb. "After Each Prayer: The Báb on Remembering Parents." *Selections from the Writings of the Báb*, Bahá'í World Centre, n.d..

Chicago:
the Báb. "After Each Prayer: The Báb on Remembering Parents." In *Selections from the Writings of the Báb*, Bahá'í World Centre, n.d..