The grand point of the New Covenant is one mercy and grace to ALL. That is literally ALL, both Jews and gentiles, that is to say all of the nations of this world. Even so, it is a powerful sub point that the Jews should have priority, that

The Jews should have priority in the
preaching of the gospel !

Jesus did not come to destroy Moses’ law., Mtt 5:17.

“For most assuredly, I tell you, until heaven and earth pass away, not even one smallest letter or one tiny pen stroke shall in any way pass away from the law, until all things are accomplished.”
Mtt 5:18

So a special prophet was to come who come who is like, Moses, whom everyone has to listen to, Deut 18:15. And like Moses? One of the most prominent things is He would be one who speaks to God face to face (Ex 33:11, etc.) and who delivers God’s laws.

So what was Jesus agenda?

He told the Canaanite woman,

“I wasn’t sent to anyone but the lost sheep of the house of Israel.”
Mtt 15:24

When Jesus named His twelve apostles in Matthew 10, and sent them out on the limited commission, the emphasis was to be in saving the Jews, and indeed, to not go to ANYONE else. He gave them authority over unclean spirits and every disease (and this group included Judas), and told them,

5 … “Don’t go among the Gentiles, and don’t enter into any city of the Samaritans. 6 Rather, go to the lost sheep of the house of Israel. 7 As you go, preach, saying, ‘The Kingdom of Heaven is at hand!’”
Mtt 10:5-7

For sure that was so, unless you want to maintain that Jesus badly misunderstood the situation. He clearly knew early in His ministry to the Jews would reject Him (Jn 2:19-22). This was not a surprise. Even so God said,

“It shall happen, that whoever will not listen to my words which he shall speak in my name, I will require it of him.”
Deut 18:19

So Jesus told this apostles on this first mission of those who would reject the words He was sending,

“Most assuredly I tell you, it will be more tolerable for the land of Sodom and Gomorrah in the day of judgment than for that city.”
Mtt 10:15

All through history, Jesus has wanted to unite
the Jews and give them the victory.

Jesus spoke of what He will do during the Christian age in sending the messenger whom they would kill and crucify, Mtt 23:32-35. Jesus mourned their hardness of heart.

“Jerusalem, Jerusalem, who kills the prophets, and stones those who are sent to her! How often would I have gathered your children together, even as a hen gathers her chickens under her wings, and you would not!”
Mtt 23:37

Still Jesus pointed to better days.

“For I tell you, you will not see me from now on, until you say, ‘Blessed is he who comes in the name of the Lord!’”
Mtt 23:39

Scriptures are from the World English Bible WEB, a copyright free revision
of the original ASV American Standard Version 1901.