A.T. Robertson Commentary Matthew 27:20

"Now the chief priests and the elders persuaded the multitudes that they should ask for Barabbas, and destroy Jesus." — Matthew 27:20 (ASV)

Persuaded (επεισαν). The chief priests (Sadducees) and elders (Pharisees) saw the peril of the situation and took no chances. While Pilate wavered in pressing the question, they used all their arts to get the people to "ask for themselves" (αιτησωντα, indirect middle ingressive aorist subjunctive) and to choose Barabbas and not Jesus.