Psalm 109:24

“David, when his son was in danger after his adultery, made confession in ashes and with fasting.He tells us that he ate ashes like bread, and mingled his drink with weeping.And that his knees became weak through fasting.” — editor's note: Ps. cix. 24.

“By reason of the voice of my groaning my bones cleave to my skin.”” — editor's note: Ps. cix. 24; cii. 5.

“For if you plead that owing to weakness of the flesh you cannot get rid of your sins by fasting, and you cannot say: “My knees are weak from fasting, and my flesh is changed for oil; for I have eaten ashes for my bread, and mingled my drink with weeping,” then atone for them by profuse almsgiving.” — editor's note: Ps. cviii. (cix.) 24; ci. (cii.) 10.

““I became also a reproach unto them” (ver. 24): through the death of the Cross.” — the author cites it