A widow - This is a circumstance that gives increasing interest to the parable. Judges were bound to show special attention to widows, Isaiah 1:17; Jeremiah 22:3. The reason of this was that they were defenseless, were commonly poor, and were liable to be oppressed by those in power.
Avenge me - This would have been better translated, "Do me justice against my adversary, or vindicate me from him." It does not denote vengeance or revenge, but simply that she wished to have "justice" done her - a thing which this judge was "bound" to do, but which it seems he had no disposition to do.
Adversary - One opposed in law. In this case it seems that the judge was unwilling to do justice, and probably took advantage of her condition to oppress her.

Avenge me of mine adversary - The original, εκδικησον με απο του αντιδικου μου, had better be translated, Do me justice against, or vindicate me from, my adversary. If the woman had come to get revenge, as our common translation intimates, I think our blessed Lord would never have permitted her to have the honor of a place in the sacred records. She desired to have justice, and that only; and by her importunity she got that which the unrighteous judge had no inclination to give, but merely for his own ease.

And there was a widow in that city,.... Poor and helpless, and none among men to counsel, direct, and assist her, and take her part: now as in the accommodation of this parable, the elect of God answer to this widow; such an one is rather pitched upon to represent the helpless, desolate, and forlorn condition they are in among men in this world, though they are espoused to one husband, Christ; and especially to signify the state and condition of God's elect among the Jews in those sad times, before the destruction of Jerusalem, this parable has respect unto. Christ is the bridegroom of his church and people; he is their husband, the Lord of hosts is his name; and they are espoused as a chaste virgin to him; and whilst he was here on earth, his disciples, who were the children of the bridegroom, could not fast and mourn, for which they had no reason; but upon the death of Christ, when he was removed from them, they had great sorrow of heart; they were left like widows and orphans; hence those words of Christ, John 14:18 and were persecuted by the Jews in their own land; and wherever they went, they stirred up the Gentiles against them; and so things continued till near the destruction of Jerusalem; during which time many a request was made to God, the judge of the widows and fatherless, to the following purport:
and she came unto him, saying, avenge me of my adversary; or do me justice in the cause depending between me, and him that has wronged me; hear the cause, and do right; vindicate, and deliver me. Many are the adversaries of God's people, as the sins and corruptions of their own hearts, Satan, and his angels, wicked oppressors, and persecutors; the last seem, in the mystical sense, to be designed here: it is lawful to pray for vengeance on them; it is right to apply to God, and leave it with him, to whom it belongs; and it has been the suit and cry of the best of men; see Revelation 6:9. It does not become the people of God to avenge themselves, even when it is in the power of their hands; nor should they desire it for their own sakes, so much as for the glory of God; they should ask it, not to gratify a revengeful spirit in them, but for the honour or divine justice; and this should be always with submission to the will of God, leaving it to his own time and way, to whom vengeance belongs, and who has said it is mine, and I will repay it; as he certainly will sooner or later: the purity of his nature, his abhorrence of sin, and sinful men, and his love to his own people engage him to it.

came--kept coming. See Luke 18:5, "her continual coming."
Avenge me--that is, rid me of the oppression of.