Isaiah 58 is a reading for Lent. Buried in this chapter is a discussion of a favorite Lenten practice – fasting. The discussion describes the fasting God expects, and it makes our timid and small efforts at fasting appear pitiful in comparison. Lent isn't so much about fasting – at least the way we usually practice fasting during this season, but is more about self-denial and reflection. Many of us give up something relatively easy to give up during Lent and think this satisfies the perceived obligation, but this sort of fasting isn't the fasting expected by God.
Verse 5 describes the kind of fasting, or penitence that we normally consider appropriate during both Lent and at other fasting times. This verse reads: "Is such the fast that I choose, a day for a person to humble himself? Is it to bow down his head like a reed, and to spread sackcloth and ashes under him?" (ESV) That sounds like what we often consider fasting and penitence – self denial, and the practice of individual rites of fasting that demonstrate that we are fasting.
But verse 6 tells us we're wrong if we think God wants this kind of fasting: "Is this not the fast that I choose: to loose the bonds of wickedness, to undo the straps of the yoke, to let the oppressed go free, and to break every yoke? Is it not to share your bread with the hungry and bring the homeless poor into your house; when you see the naked, to cover him, and not hide yourself from your own flesh?" (ESV)
Fasting in this passage is much more broad and demanding than our normal understanding of it. In this passage, fasting isn't focused on God, or our own penitence. Rather, this fasting is other-focused, and directly affects community. Self-denial in this passage is the sacrificial giving, not to church treasuries, but to those who need help.
I say fasting is sacrificial giving because of the wording of verse 10: "If you pour yourself out for the hungry and satisfy the desire of the afflicted, then shall your light rise in the darkness and your gloom be as the noonday." (ESV)
Did you get that? "Pour yourself out…" That is sacrificial giving to others. This echoes Paul's "if I pour myself out…." which means that he has given everything he has – his life's focus, his efforts, his riches – for the sake of the Gospel. This is fasting as God understands it – as God expects it. How are you doing?