Exegesis:

anagkēn de eichen apoluein autois kata heortēn hena lit. ‘he had the compulsion, i.e. he was obliged, to release for them one (person) at a feast’; here anagkē refers to a compulsion by tradition. For kata heortēn.

Translation:

To them, referring to the beneficiaries, may have to be described, e.g. by ‘as-a-kindness-to them’ (cf. Balinese), ‘according to their choice’ (Willibrord), ‘as they requested.’ The pronoun refers to the inhabitants of Jerusalem, hence ‘the populace’ (Bahasa Indonesia RC), ‘the crowd’ (Javanese), or to the whole people, as represented by their leaders and the populace of Jerusalem, hence ‘the Jews,’ or, ‘the Jewish people’ (Sundanese, Balinese).

At the festival, or more specifically, “at each Passover Feast” (Good News Translation); cf. above on 2.41.

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.