Isaiah 58:4

Ye fast for strife and debate; your fasting days, wherein you ought in a special manner to implore the mercy of God, and to show compassion to men, you employ in a great measure in injuring or quarrelling with your brethren, your servants, or debtors, or in contriving mischief against them, as if the design of your fasting and praying to God were only to obtain a licence to oppress men. Compare Matthew 23:14. With the fist of wickedness; or, with a wicked fist; a genitive of the adjunct. To deal rigorously and injuriously with your servants or debtors; which servants, it may be, had sold themselves to the year of redemption, Exodus 21:2 Leviticus 25:39,40,50. You handle them with a hard hand; the word is used for fist, Exodus 21:18; the LXX. add the humble, poor, or inferior person; and that not only their debtors, with a summum jus, exact rigour, which seems elsewhere to be expressed by grinding the face; Isaiah 3:15, and in that parable by taking by the throat, Matthew 18:28; but also their servants out of mere will and pleasure, and in contempt of them, treating them opprobriously, as Christ was handled in contempt and scorn, Matthew 26:67,68 Joh 18:22. Your voice; either,

1. In strife and debate, in which men's passions show themselves by loud clamours. Or,

2. So as to cause the cry of the oppressed, by reason of your injuries, of what kind soever, to enter into the ears of God; which is a crying sin, whether it proceed from unmercifulness, Exodus 22:25, which sometimes increaseth to rage, 2 Chronicles 28:9; or from injustice, Isaiah 5:7; or from fraud and deceit, James 5:4. The Scripture doth frequently express whatever sin is against charity in special, as also general complex sins, by crying, Genesis 18:20, 1 John 1:2. Or,

3. By way of ostentation, to note their hypocrisy; they love to be taken notice of by others, Mt 6 2,5,16; or their folly, supposing that they shall be heard for their much speaking, upon which account Baal's priests are mocked by Elijah, 1 Kings 18:27,28 4. Voice here relates principally to their prayer; it is a synecdoche of the kind: so the sense is, This is not the way to have your prayers heard; if you desire that, you must first in another manner, and abstain from all kind of oppression. And this seems best to suit the context, which is to show what kind of fast the Lord reproves, and what he approves in the following verses.