One of prayer’s companions is fasting. We see this in Psalm 35:13-14.
Ruthless witnesses come forward;
they question me on things I know nothing about.
12 They repay me evil for good
and leave me like one bereaved.
13 Yet when they were ill, I put on sackcloth
and humbled myself with fasting.
When my prayers returned to me unanswered,
14 I went about mourning
as though for my friend or brother.
I bowed my head in grief
as though weeping for my mother.
they question me on things I know nothing about.
12 They repay me evil for good
and leave me like one bereaved.
13 Yet when they were ill, I put on sackcloth
and humbled myself with fasting.
When my prayers returned to me unanswered,
14 I went about mourning
as though for my friend or brother.
I bowed my head in grief
as though weeping for my mother.
John Goldingay says that “David’s sadness was not yet fully bloomed until his body – in this case, fasting – was involved." (In McKnight, Fasting: The Ancient Practices, xiii. Note McKnight's book is an excellent summary of the practice of fasting.)
Scot McKnight writes: These verses assume "that merely to feel sadness is not enough; because we are physical creatures and not just minds and spirits, it would be odd not to express sorrow in (e.g.) abstention from food and then afflicting one’s spirit and one’s self.”” (McKnight, xiii)
