A judge, acting as an emissary of God in the search for truth and justice, must put aside his personal feelings — personal and philosophical — in order to adjudicate fairly.
He cannot disregard the facts and side with a poor petitioner over a wealthy one because he feels the wealthy one can better “afford” to lose.
He must decide according to the law.
Similarly, a prophet can only prophesy when he transcends himself and becomes a conduit for God’s words.
As we read in Kings II (3:11-15), when Elisha becomes angry – that is, when his ego is engaged – he cannot prophesy.
–Rabbi Adin Steinsaltz