Albert Barnes Commentary Psalms 83:5

"For they have consulted together with one consent; Against thee do they make a covenant:" — Psalms 83:5 (ASV)

For they have consulted together with one consent—Margin, as in Hebrew, heart. There is no division in their counsels on this subject. They have one desire—one purpose—in regard to the matter. Pilate and Herod were made friends together against Christ (Luke 23:12); and the world, divided and hostile on other matters, has been habitually united in its opposition to Christ and to a pure and spiritual religion.

They are confederate against you—literally, “They cut a covenant against you;” that is, they ratify such a covenant, compact, league—referring to the manner in which bargains and agreements were ratified by cutting in pieces a victim sacrificed on such occasions; that is, by giving to such a transaction the solemnity of a religious sanction (Genesis 15:10; Jeremiah 34:18–19). See Bochart, Hieroz. i. 35. The meaning here is, that they had entered into this agreement in the most solemn manner, under the sanctions of religion.