The context of this passage is the theme of fasting. Isaiah is speaking on God's behalf of what type of fasting he desires and what type of fasting he does not desire. The type of fasting that God loves is the type of fasting that is consistent with love and compassion. Here is a quotation that shows this; it comes from Isaiah 58:6-7:
“Is not this the kind of fasting I have chosen:
to loose the chains of injustice
and untie the cords of the yoke,
to set the oppressed free
and break every yoke?
Is it not to share your food with the hungry
and to provide the poor wanderer with shelter—
when you see the naked, to clothe them,
and not to turn away from your own flesh and blood?"
In light of this, the type of fasting that he does not desire is the type that puts a yoke (of burden) on people, a fasting that points fingers at others in a condemnatory way, and a fasting that speak vainly. In a word, we can say it is a theology that states: "God gives grace to the humble and he opposes the proud."