“The voluntary abstention from an otherwise normal function – most often eating – for the sake of intense spiritual activity.”

“Yet even now, says the Lord,
return to me with your all your heart,
with fasting, with weeping, and with mourning.” — Joel 2:12

from A Year with God:  Living out the Spiritual Disciplines edited by  Richard J. Foster and Julia L. Roller, introduction to days 226 – 245.