Continuing on from Isaiah 58:5.
 Is it a fast that I have chosen, A day for a man to afflict his soul? Is it to bow down his head like a bulrush, And to spread out sackcloth and ashes? Would you call this a fast, And an acceptable day to the LORD?
God here is again lamenting the fact that the fast that He has prescribed is not what the people are choosing to do. The people are seeing the prayer and fast as a burden to their soul. Plus they have an outward show to everyone that they are fasting. God’s question at the end of verse 5 ‘would you call this a fast, and an acceptable day to the LORD?’, is probably rhetorical as He goes onto answer it in the next few verses.
God is chastening His people because they see the Prayer and fast as a burden. I believe the lesson for us is that we must see prayer and fasting as an opportunity for tremendous blessing. We often think that a prayer and fast is coming up and the natural man does not look forward to denying pleasures and food so we think of it as a burden. If we use the Spirit of God then we will seize every opportunity to pray and fast as it will be blessing upon blessing.
 ‘Is this not the fast that I have chosen: To loose the bonds of wickedness, To undo the heavy burdens, To let the oppressed go free, And that you break every yoke?  Is it not to share your bread with the hungry, And that you bring to your house the poor who are cast out; When you see the naked, that you cover him, And not hide yourself from your own flesh?
Our Lord is here declaring the benefits of the fast that He has chosen. As I read these verses it would seem to me that verse 6 is saying when we fast according to the way that our Lord would like us to fast then He will do those things that He has promised. That is, set us free from evil, get rid of the burdens, set us free and break the heavy yoke.
Verse 7, then puts the responsibility on us to share out those things that our Lord has blessed us with, to those less fortunate. Share those things that our Lord has blessed us with both spiritual and physical things.
As the next few verses start with ‘then shall…’, that’s where the promises about the results of fasting begin. So these two verses 6 and 7 are summarising the previous ones about how to approach God’s fast: Stop making your people work while you fast; Share your wealth; Care for the poor and homeless. That’s the acceptable way to fast. Then your fasting will be acceptable to God and all the blessings will flow.
The Lord has promised to bless us and to prosper but only if we put Him first and Seek Him in everything that we do. Read Luke 12:22-31 again.
I believe that God here is promising that if we do the prayer and fasting His way then he will abundantly bless us. However once we are blessed then we should not use the blessings that He has given us to ‘feather our own nest’ but to be willing to share those blessings both spiritually and physically with those that are blind, destitute and naked spiritually.
The previous day’s message is here.
The next and final message is here.