Luke 12:57 - Ellicott's Commentary On The Whole Bible

Yea, and why even of yourselves judge ye not what is right? — Better, judge that which is just. The meaning of the words is not that they did not know what was right, but that they did not act upon their knowledge. They were passing an unrighteous judgment on the preachers of repentance, on the Baptist and on the Christ, because they came to tell them of the time of their visitation, when their action ought to have been as true and spontaneous as their daily judgment about the weather. It is possible, though not, I think, probable, that the question “Why even of yourselves...” may have some reference to the request of the disciple, in Luke 12:13, that our Lord would act as judge.