Psalms 43:1

1. Judge me, O God It was David’s habit to appeal his cause to God, because he would be judged only by the divine law and justice. Psalms 7:8; Psalms 26:1.

Plead my cause The petition is, that God would enter as a third person in the suit, or controversy, and argue and conduct it for the petitioner. It answers exactly to the idea of intercessor or advocate. See Psalms 35:1; Heb 9:24 ; 1 John 2:1.

Ungodly nation It may mean a nation devoid of piety, or one not kindly disposed, unmerciful, hostile. So Psalms 12:1. Entering the controversy in behalf of David, God is asked to do, in word or deed, whatever the equity of the case, or the chosen mode of controversy, calls for.

Deceitful and unjust man This may apply to Ahithophel, or, taking the noun collectively, to any man of his class.