A.T. Robertson 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)

For before they were at enmity between themselves (προυπηρχον γαρ εν εχθρα οντες προς εαυτους). A periphrastic imperfect of the double compound προυπερχω, an old verb, to exist (υπαρχω) previously (προ-), here alone in the N.T., with οντες (participle of ειμ) added.