For starters, there's no guarantee that Herod actually wanted to kill Jesus though it's likely.
Ellicott's Commentary [1] presents three possibilities for Luke 13:31, 'for Herod will kill thee.':
- The Pharisees’ had genuine concern: The Pharisees might have
reported what they actually knew, out of feelings more or less
friendly to Jesus.
- The Pharisees’ lies: The Pharisees might have invented a false tale
in order to get rid of Jesus’ presence among them.
- Herod actually gave the threat: The Pharisees might have been sent
by Herod to announce his purpose as a threat that he might be rid of
Jesus. This is supported by Jesus’ response, “Go tell that fox . .
.”.
Let's assume Herod gave the threat.
Superstition: Herod was somewhat of a lunatic, having killed John the Baptist, and imagining Jesus to be John reincarnated. This superstition might have prevented him from killing Jesus.
Matthew 14:3-5 and Mark 6:14-20 tell us that Herod hated John the
Baptist and consequently killed him and then was afraid that John had
been resurrected as Jesus Christ. [2]
Mark 6:14-20 NKJV says:
King Herod heard about this, for Jesus’ name had become well known.
Some were saying, “John the Baptist has been raised from the dead, and
that is why miraculous powers are at work in him.”
15 Others said, “He is Elijah.”
And still others claimed, “He is a prophet, like one of the prophets
of long ago.”
16 But when Herod heard this, he said, “John, whom I beheaded, has
been raised from the dead!”
17 For Herod himself had given orders to have John arrested, and he
had him bound and put in prison. He did this because of Herodias, his
brother Philip’s wife, whom he had married. 18 For John had been
saying to Herod, “It is not lawful for you to have your brother’s
wife.” 19 So Herodias nursed a grudge against John and wanted to kill
him. But she was not able to, 20 because Herod feared John and
protected him, knowing him to be a righteous and holy man. When Herod
heard John, he was greatly puzzled; yet he liked to listen to him.
Herod shrank from laying hands on him, though, for the memory of the
murdered friend of Jesus was a terrible one, we know, to the
superstitious tetrarch, and he dreaded being forced into a repetition
of the judicial murder of John the Baptist. [3]
Jesus was innocent:
When Pontius Pilate sent Jesus to Herod for trial because Jesus was
from Galilee, Herod was afraid of the chief priests and Sanhedrin.
Rather than seeking the truth from Jesus, Herod wanted him to perform
a miracle for his entertainment. Jesus would not comply. Herod and his
soldiers mocked Jesus. Then, instead of freeing this innocent man,
Herod sent him back to Pilate, who had the authority to have Jesus
crucified.
Herod's treachery improved his relationship with the chief priests and
Sanhedrin and started a friendship with Pilate from that day forward. [4]
We see Pilate say in Luke 23:14-16:
said to them, “You have brought this Man to me, as one who misleads
the people. And indeed, having examined Him in your presence, I have
found no fault in this Man concerning those things of which you accuse
Him; 15 no, neither did Herod, for I sent you back to him; and
indeed nothing deserving of death has been done by Him. 16 I will
therefore chastise Him and release Him”
Threat perception: If Herod did give the threat then it makes sense that Herod felt threatened by Jesus, as indicated by the warning. However, it may be that when Jesus was brought before him, Herod might have realized that Jesus was not the political threat he thought he was.
Herod didn't have the power to crucify Him. Jesus’ crucifixion was His destiny. Therefore, Jesus might have wanted to avoid being sentenced by Herod. Under Herod’s authority (as a Jewish ruler), Jesus would not have been crucified as that was a Roman practice. Instead he could have possibly been beheaded like John. That would not have fullfilled prophecy.
Psalm 22:16 NKJV
16 For dogs have surrounded Me; The congregation of the wicked has
enclosed Me.
They pierced My hands and My feet;
