John Calvin Commentary Isaiah 1:17

"learn to do well; seek justice, relieve the oppressed, judge the fatherless, plead for the widow." — Isaiah 1:17 (ASV)

Learn to do well. As he had just now, in enjoining them to cease to do evil, charged them with the continual practice of iniquity, as if he had said that their whole life was a constant habit of sinning; so now he enjoins them to become skilled in acts of kindness. In entreating them to learn this, he addresses them as students who have not yet learned their earliest lessons. And first, he commands them to seek judgment. Others translate it as 'inquire concerning judgment,' which I do not approve of; for by the word seek, the Prophet meant more than this; he meant what we call the actual practice of it. By the word judgment, he denotes what is good and right, as if he had said, “Aim at uprightness.”

Relieve the oppressed. The Prophet, after his usual manner, adds the mention of particular groups to the general description. Although he has already given a special exhortation to kindness and justice, yet, wishing to press them more closely, he enters into a more careful enumeration of certain groups to present a more complete view of the subject. For otherwise, men always wish to be considered good and righteous and can scarcely be moved by general instruction; but when we come to particular cases, they are forced, as it were, to deal with the matter at hand and are compelled to yield, or at least become more tractable—something we experience daily.

Judge the fatherless, plead for the widow. The Prophet here selects two groups by means of which the wickedness of men is more fully exposed. For it seldom happens that the causes of the fatherless and widows are defended, because men do not expect any rewards from them. They are exposed to every kind of injustice to such an extent that no one comes forward in their defense, because there is no one who follows justice for its own sake. And not only that, but there is a very great number of people who are ready to plunder the poor and needy.

This proves that there is no one who cares about exercising judgment. For we need not wonder at all that men of wealth and influence have friends to assist them, who are motivated and attracted by the expectation of reward. But the Lord declares that He takes charge of the fatherless and widows and will avenge them if they sustain any injury.

Ye shall not afflict any widow, or fatherless child. If thou afflict them in any wise, and they cry at all unto me, I will surely hear their cry: and my wrath shall wax hot, and I will kill you with the sword; and your wives shall be widows, and your children fatherless (Exodus 22:22–24).

The same declaration is now extended to all others who are oppressed and groan under the violence and lawless passions of men of rank and influence.

This should yield the highest consolation to all the children of God, who are enjoined to possess their souls in patience (Luke 21:19). Whatever the haughty boasting of enemies may be, this will not prevent the people of God from glorying in the midst of their tribulations, as long as such considerations as these have an abiding place in their minds: “The Lord will be our avenger. Though men disregard us, He takes care of us. He will aid the destitute and will defend their cause.”