John Gill Commentary 2 Chronicles 19:6

"and said to the judges, Consider what ye do: for ye judge not for man, but for Jehovah; and [he is] with you in the judgment." — 2 Chronicles 19:6 (ASV)

And said to the judges, take heed what you do
In judgment, that they judged righteous judgment according to the law of God, without partiality and respect of persons:

for you judge not for man, but for the Lord ;
not for man only, but for the Lord; and not so much for man as for the Lord, whom they represented in judgment; whose law was the rule of their judgment, and whose glory their end, and to whom they were accountable:

who is with you in the judgment :
as to guide and direct you, so to observe how they behaved, and be a witness for or against them; the Targum is, you judge not before men, but before the Word of the Lord, whose Shechinah dwells with you in the affair of judgment.