Charles Ellicott Commentary Psalms 2:5

"Then will he speak unto them in his wrath, And vex them in his sore displeasure:" — Psalms 2:5 (ASV)

Then. —An emphatic particle, marking the climax; possibly equal to “Look! Behold!” The grand roll of the words in the original is like the roll of thunder, and is rendered more effective by its contrast with the quiet manner of Psalm 2:4.

And vex them. —Literally, and greatly (the verb is in the intensive conjugation) terrify them in his nostrils and in his heat.