Isaiah 58: unmerciful people who searches for Lord's wisdom

In Isaiah 58, there is a question:
Israel think of themselves as very devoted and show interest in learning more from the Lord (to get wisdom). 

 ² Yet they seek Me day by day and delight to know My ways,
As a nation that has done righteousness
And has not forsaken the ordinance of their God.
They ask Me for just decisions,
They delight in the nearness of God.

They fast and keep the Sabbath. So, they ask themselves: Why are we  ill-treated by the Lord?
The Lord answers saying that He is not so pleased by great demonstrations of humility, but much more of mercy:

5
Is it a fast like this that I choose, a day for a person to humble himself?
Is it for bowing [b]one’s head like a reed
And for spreading out sackcloth and ashes as a bed?
Will you call this a fast, even an acceptable day to the Lord?
6
Is this not the fast that I choose:
To release the bonds of wickedness,
To undo the ropes of the yoke,
And to let the oppressed go free,
And break every yoke?
7
Is it not to break your bread [c]with the hungry
And bring the homeless poor into the house;
When you see the naked, to cover him;
And not to hide yourself from your own flesh?
8
Then your light will break out like the dawn,
And your recovery will spring up quickly;
And your righteousness will go before you;
The glory of the Lord will be your rear guard.


Therefore, it is very important to pay attention to the needy, specially inside the church. I am very selfish, but this text is saying to me: pay attention to your siblings in the church! Church is not a place to show yourself as a respectful guy.

13
“If, because of the Sabbath, you restrain your foot
From doing as you wish on My holy day,
And call the Sabbath a pleasure, and the holy day of the Lord honorable,
And honor it, desisting from your own ways,
From seeking your own pleasure
And speaking your own word,
14
Then you will take delight in the Lord,
And I will make you ride on the heights of the earth;
And I will feed you with the heritage of Jacob your father,
For the mouth of the Lord has spoken.”

In verse 13, the Lord is asking to restrain my foot to do as I wish. In my selfishness I don't want to help others, for instance; however, the Lord wants me to call the Sabbath a pleasure when I desist from my own ways. In doing so, the reward is to take delight in the Lord.