There is no extrabiblical evidence for the custom to which Pilate refers. According to Matthew 27.15, At every Passover Festival the Roman governor was in the habit of setting free any one prisoner the crowd asked for (compare Mark 15.6). According to Luke 23.17, which is textually uncertain, At every Passover Festival Pilate had to set free one prisoner for them.

Set free a prisoner is literally “set free someone.” New English Bible and Jerusalem Bible translate “one prisoner.”

It may be misleading to translate literally according to the custom you have. It would imply in some languages that the Jews themselves had a custom of freeing a prisoner. A more appropriate translation may be “It is customary for me to set free a prisoner for you during the Passover” or even “Customarily I set free a prisoner for you during the Passover” or “… at the time of each Passover.” In some languages it may be necessary to indicate that this was a yearly event, for example “… each year at the time of the Passover Festival.”

For Jesus as the king of the Jews see verse 33. It is uncertain why Pilate continues to refer to Jesus by this title after he has declared him innocent (verse 38).

To render satisfactorily the phrase for you, it may be necessary to translate “Do you want me to do you a favour by setting free the King of the Jews?” This statement is awkward to translate since Pilate addresses the Jews themselves as “you” and then speaks of Jesus as “the King of the Jews.” In some languages one may say “Do you want me to do you the favour of setting free your king?” Otherwise, readers might assume that Pilate was either addressing non-Jews, or that he was telling Jews about someone who ruled over some other group of Jews.

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on the Gospel of John. (UBS Handbook Series). New York: UBS, 1980. For this and other handbooks for translators see here .