18 “Be mindful of this Your creature”. Of what creature of Yours? “The enemy has reviled the Lord.” O Asaph, grieve over your old blindness in understanding: “the enemy has reviled the Lord.” It was said to Christ in His own nation, “a sinner is this Man: we know not whence He is:” we know Moses, to him spoke God; this Man is a Samaritan. “And the unwise people has provoked Your name.” The unwise people Asaph was at that time, but not the understanding of Asaph at that time.
What is said in the former Psalm? “As it were a beast I have become unto You, and I am always with You:” because He went not to the gods and idols of the Gentiles. Although he knew not, being like a beast, yet he knew again as a man. For he said, “alway I am with You, like a beast:” and what afterwards in that place in the same Psalm, where Asaph is? “You have held the hand of my right hand, in Your will You have conducted me, and with glory You have taken me up.” In Your will, not in my righteousness: by Your gift, not by my work.
Therefore here also, “the enemy has reviled the Lord: and the unwise people has provoked Your name.” Have they all then perished? Far be it....For even the Apostle Paul through unbelief had been broken, and through faith unto the root he was restored. So evidently “the unwise people provoked Your name,” when it was said, “If Son of God He is let Him come down from the Cross.”
Source: The Enarrations, or Expositions, on the Psalms (New Advent)