Luke 4:16 Now Jesus came to Nazareth, where he had been brought up, and went into the synagogue on the Sabbath day, as was his custom. He stood up to read, 4:17 and the scroll of the prophet Isaiah was given to him. He unrolled the scroll and found the place where it was written,
4:18 “The Spirit of the Lord is upon me,
because he has anointed me to proclaim good news to the poor.
He has sent me to proclaim release to the captives
and the regaining of sight to the blind,
to set free those who are oppressed,
4:19 to proclaim the year of the Lord’s favor.”

Why does the quotation finish at this point?  Why did Jesus not include the words ‘…and the day of vengeance of our God’ (Isa 61:2)?

Richard Rohr (The Divine Dance) takes this as evidence that our Lord deliberately subverted such negative, punitive aspects of Old Testament teaching.

A more developed form of this argument is given by Derek Flood (Disarming Scripture).  Flood thinks that it was the omission of the ‘vengeance’ part of the quotation that led to the negative reaction of his hearers, who would have been longing for Jesus to say something about the overthrow of their Roman oppressors.

‘The omission of Isa. 61:2b probably is motivated by Luke’s intention to highlight dekton (“favor”) as the final word of his scriptural quotation. This is confirmed by the function of dektos in the discussion that follows (Lk 4:24). The suggestion [by Fitzmyer] that Isa 61:2b is omitted because Luke wanted to downplay the theme of judgment is unlikely in light of its appearance already in Lk 2:34–35; 3:7–17.’ (Commentary on the New Testament use of the Old Testament).

Given Jesus’ unwavering regard for the Scriptures, it is better simply to say that the words were omitted because were not relevant to his ministry at that time.  His was a ministry of grace, not of condemnation.

Garland agrees that ‘the effect of the omission is that the emphasis falls on the year of release, not vengeance.’  But the message of vengeance is not shunned (see Lk 21:22).  ‘It is more likely that Luke intends to present the outset of Jesus’ ministry as one marked by grace and release. John stridently harangued the crowd, who all had better repent or face a fiery judgment. By contrast, Jesus heralds that now is the time when God’s long-awaited promises are being fulfilled. Now is the time of salvation when God is acting to redeem his people.’

‘It seems likely that Jesus left out the part about judgment because the time when he will execute judgment is not tied to the phase of his ministry he was initiating, but will be a part of his later return (Heb 9:27). Jesus will eventually fulfill both aspects of Isaiah’s message, but the stress at this time was Jesus’ identity and the fact that the promise of God was fulfilled in Jesus’ mission as the Servant.’ (Holman Apologetics Commentary)

Further: ‘the day of vengeance’ would have been associated in Jewish minds with God’s judgement of the Gentiles.  But Jesus wishes to emphasise that God’s favour extends to the Gentiles themselves.

This line of interpretation is consistent with Jn 3:17f – ‘ God did not send his Son into the world to condemn the world, but that the world should be saved through him. 3:18 The one who believes in him is not condemned. The one who does not believe has been condemned already, because he has not believed in the name of the one and only Son of God.’ (My emphasis)