I have always struggled with fasting as a practice, at least in terms of food. Recently though I have begun exploring what Jesus and the prophets had to say about it, as well as what later commentators have said. I found Bible.org has an excellent summary of fasting as practiced and understood by the Hebrews in Old Testament times, which concludes as follows:
“The various references to fasting in the Hebrew Bible and Jewish tradition begin to converge in several key theological themes. The most basic ancient purpose of fasting as a sign of mourning in times of death or disaster branches into two main theological ideas, namely fasting as repentance for sin and fasting to intensify prayer when seeking God’s favour. Both of these ideas, however, presuppose an even more basic theological idea that the OT occasionally highlights through fasting references: that God is the ultimate source and sustainer of life, and human life depends on connection to his presence and obedience to his words. This theme that emerges already in the Garden of Eden is the basis for the fasting that highlights Moses as God’s chosen leader, and sets in motion a messianic motif that God’s chosen prophet will be like him. As the fasts of Israel turned routine, the prophets urged the people to true justice in anticipation of the eschatological day when their mourning would be turned to gladness, their fasting to feasting. Against the backdrop of Jewish fasting that occasionally obscured true humility, repentance and justice through hypocrisy and ritual, the eschatological realisation of the ideal that fasting anticipated came in the person of Jesus Christ.”
This matches closely to what I’ve found in the Old Testament but says it so much more succinctly than I have in my own journal notes. I look forward to seeing what they say about the New Testament references.