Charles Ellicott Commentary Luke 23:12

"And Herod and Pilate became friends with each other that very day: for before they were at enmity between themselves." — Luke 23:12 (ASV)

Before they were at enmity between themselves.—The special cause of enmity is not known. Possibly the massacre of the Galileans, mentioned in Luke 13:1, may have had somewhat to do with it. The union of the two in their enmity against Jesus, though not mentioned in the Gospels, is referred to in the first recorded hymn of the Church of Christ (Acts 4:27). Herod, however, it will be noted, passes no formal sentence. He is satisfied with Pilate’s mark of respect for his jurisdiction.