What mean ye that ye beat my people to pieces? He mentions also other particulars, from which it is evident that they ruled in a haughty, cruel and oppressive manner. It was not necessary that the Prophet should describe minutely everything deserving reproof in the princes; for from these few circumstances it is evident with what injustice and cruelty and tyranny they ruled. But to whom shall the poor betake themselves but to the magistrate, who ought to be the father of his country and the protector of the wretched? On this account he employs a vehement interrogation, What? as if he had said, "What effrontery is this! What cruelty and barbarity, to abuse the mean condition of the poor, so as to have no compassion on them!" By two comparisons he describes their cruel oppression mingled with pride. Saith the Lord Jehovah of hosts. That the reproof may have all the weight that it ought to have, he brings forward God as speaking; for there is an implied contrast that these things should not be viewed as coming from the mouth of men, but that the accusation proceeds from God himself, and that he pursues those who are guilty of such injustice, and will at length take vengeance on them. Because those who have been exalted to any kind of honor conduct themselves so haughtily as to disdain every direction and advice, he therefore meets their pride by bringing forward the majesty of God, that they may not venture to despise his earnest and severe threatenings. Yet let us remember that this passage ought not to be understood as if the Prophet were speaking only about the mercy of God; for after having threatened vengeance indiscriminately on all, he particularly mentions those who are their heads, in order to show that no man can escape the arm of God: and here he employs what is called the argument from the greater to the less." How would the Lord spare the lowest of the people, when he punishes even the princes themselves, because they have destroyed the vineyard?"

What mean ye - What is your object? Or, What advantage is it to you? Or, By what right or pretence do you do this?
Beat my people to pieces - That is, that you trample on them; or cruelly oppress them; Psalm 94:5.
And grind the faces of the poor - This is an expression also denoting great oppression. It is taken from the act of grinding a substance on a stone until it is worn away and nothing is left. So, by their cruel exactions, by their injustice to the poor, they exhausted their little property until nothing was left. The word "faces" here is synonymous with "persons" - or with the poor themselves. The word "face" is often used in the sense of "person;" Exodus 33:14; 2-Samuel 18:11. A similar description, though in still stronger language, is found in Micah 3:2-3 :
Who pluck off their skin from off them,
And their flesh from off their bones;
Who also eat the flesh of my people,
And flay their skin from off them;
And they break their bones, and chop them in pieces,
As for the pot, and as flesh within the caldron.

And grind the faces - The expression and the image is strong, to denote grievous oppression but is exceeded by the prophet Micah, Micah 3:1-3 : -
"Hear, I pray you, ye chiefs of Jacob,
And ye princes of the house of Israel:
Is it not yours to know what is right?
Ye that hate good and love evil:
Who tear their skins from off them,
And their flesh from off their bones;
Who devour the flesh of my people;
And flay from off them their skin;
And their bones they dash in pieces;
And chop them asunder, as morsels for the pot:
And as flesh thrown into the midst of the caldron."
In the last line but one, for כאשר keasher, read, by the transposition of a letter, כשאר kisher, with the Septuagint and Chaldee.

What mean ye [that] ye beat my people to pieces, (m) and grind the faces of the poor? saith the Lord GOD of hosts.
(m) That is, you show all cruelty against them.

What mean ye, that ye beat my people to pieces,.... Reduce them to the utmost poverty; so the Targum,
"wherefore do ye impoverish my people?''
as they did by exacting tithes of all that they possessed; by requiring large sums for their long prayers; and by various traditions they enjoined them to observe:
and grind the faces of the poor? either by smiting them on the cheek, as Christ, who became poor for our sakes, was smitten by them; or by bringing them into such low circumstances, by their exorbitant demands, that they had not sufficiency of food to eat; by which means their faces became pale, thin, and meagre:
saith the Lord God of Hosts: who saw all their actions, and was able to plead his people's cause, and take vengeance on their oppressors.

What right have ye to beat, &c. (Psalm 94:5; Micah 3:2-3).
grind--by exactions, so as to leave them nothing.
faces--persons; with the additional idea of it being openly and palpably done. "Presence," equivalent to "face" (Hebrew).