God spoke to the people through the prophet Isaiah in chapter 58:

“Is not this the kind of fasting I have chosen:

… 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?

Then your light will break forth like the dawn,
    and your healing will quickly appear;
then your righteousness will go before you,
    and the glory of the Lord will be your rear guar...