Albert Barnes Commentary Luke 18:3

"and there was a widow in that city; and she came oft unto him, saying, Avenge me of mine adversary." — Luke 18:3 (ASV)

A widow. This is a circumstance that gives increasing interest to the parable. Judges were bound to show peculiar attention to widows (Isaiah 1:17; Jeremiah 22:3). The reason for 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 for 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.