A.T. Robertson Commentary Luke 18:6

"And the Lord said, Hear what the unrighteous judge saith." — Luke 18:6 (ASV)

The unrighteous judge (ο κριτης της αδικιας). The judge of unrighteousness (marked by unrighteousness), as in 16:8 we have "the steward of unrighteousness," the same idiom.