Exegesis:

eipen de Hērōdēs ‘and (considering these statements) Herod said,’ scil. to himself.

Iōannēn egō apekephalisa ‘John I have beheaded.’ egō is emphatic (cf. New English Bible), the thought connexion being: it is impossible that he is John, I have seen to that (cf. Klostermann).

apokephalizō ‘to behead,’ ‘to execute by beheading.’

tis de estin houtos peri hou akouō toiauta? ‘who is this about whom I hear such things?’ toiauta refers to ta ginomena.

kai ezētei idein auton ‘and he tried to see him,’ i.e. he tried to find a way to meet him, cf. on 5.18.

Translation:

John I beheaded, or, “John? I beheaded him” (The Four Gospels – a New Translation). Herod is the initiator, not the direct agent. The verb is in some languages rendered by a verbal derivation of ‘head’ (Greek, English, French, Tae’), in some others by ‘to cut (off) his head’ (Batak Toba), ‘to cut (through) his neck’ (Sundanese).

But who is this about whom I hear such things? This sentence may better be divided in two, ‘But who is this?’ (for which cf. on 5.21), and, ‘I hear strange (or, extraordinary) things about him,’ ‘I hear reports about him which I cannot believe.’

He sought to see him, or, ‘to met him.’ For the first verb cf. on 5.18.

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.