As I read the complaint against the people, i see that there are two kinds of days.
The first day seems to be problematic. See highlights in v. 1-5
“Cry aloud; do not hold back;
lift up your voice like a trumpet;
declare to my people their transgression,
to the house of Jacob their sins.
2 Yet they seek me daily
and delight to know my ways,
as if they were a nation that did righteousness
and did not forsake the judgment of their God;
they ask of me righteous judgments;
they delight to draw near to God.
3 ‘Why have we fasted, and you see it not?
Why have we humbled ourselves, and you take no knowledge of it?’
Behold, in the day of your fast you seek your own pleasure,
and oppress all your workers.
4 Behold, you fast only to quarrel and to fight
and to hit with a wicked fist.
Fasting like yours this day
will not make your voice to be heard on high.
5 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?
Will you call this a fast,
and a day acceptable to the Lord?
The issue here is tokenism. By the standards of faith as checking off the boxes of obligation, they seem to be doing well. They seek God and fast, or so it would seem. But this kind of day, dedicated to fasting or prayer or procession makes no change in the participants and it makes no change in the community. The poor are still poor and the workers are still not paid well.
The last verses talk about another day – the Sabbath. It is a good day:
13 “If you turn back your foot from the Sabbath,
from doing your pleasure on my holy day,
and call the Sabbath a delight
and the holy day of the Lord honorable;
if you honor it, not going your own ways,
or seeking your own pleasure, or talking idly;
14 then you shall take delight in the Lord,
and I will make you ride on the heights of the earth;
I will feed you with the heritage of Jacob your father,
for the mouth of the Lord has spoken.”
This Sabbath day has the advantage in that it is commanded. In addition, it seems to be important in going beyond tokenism to a transformation. How is this the case? It must mean that the Sabbath as intended, was not a day of obligation to be checked off, but a day of rest from work so one can get to know God and his ways. (notice v. 14)
The Day God chose was a day that was part of a lifestyle of knowing God and keeping his ways. Not a token day of words without actions.
The Fast that the people chose was token, a show of religion, a way to justify yourself that you are doing something. The Fast that God chooses is one that is transformational – our lives get a different focus, our goal is to change “structural evil” ( v. 6) and to personally help others (v. 7).
6 “Is not this 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?
7 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 to hide yourself from your own flesh?
We don’t have this in our culture? After all, who keeps a Sabbath any longer? We don’t. We are hurrying to a benefit concert, a walk for a cause or bringing a canned food item to the football game we rush to each Sunday.