What did God mean when he said Israel is his firstborn son?

In the bible we know that although firstborn implies being first, it could also just mean you have a high/favored position. Esau traded his birthright to his brother Jacob

Genesis 25:33,34
And Jacob added: “Swear to me first!” So he swore to him and sold his right as firstborn to Jacob.h 34 Then Jacob gave E′sau bread and lentil stew, and he ate and drank, and he got up and went away. Thus E′sau despised the birthright.

So it's not hard to see that Israel's firstborn-(likeness) was symbolic

Deuteronomy 7:6
For you are a holy people to Jehovah your God, and Jehovah your God has chosen you to become his people, his special property,a out of all the peoples who are on the face of the earth

Exodus 19:5'6
Now if you will strictly obey my voice and keep my covenant, you will certainly become my special propertya out of all peoples, for the whole earth belongs to me. 6 You will become to me a kingdom of priests and a holy nation.’ These are the words that you are to say to the Israelites

Romans 9:4
who are Israelites. To them belong the adoption as sons and the glory and the covenants and the giving of the Law and the sacred serviced and the promises.

Hosea 11:1
When Israel was a boy, I loved him,a
And out of Egypt I called my son.

Deuteronomy 7:8
Rather, it was because of Jehovah’s love for you and because he kept the oath that he had sworn to your forefathers

Amos 3:1,2
Hear this word that Jehovah has spoken concerning you, O people of Israel, concerning the whole family that I brought up out of the land of Egypt:
2.You alone I have known out of all the families of the earth.

That is why I will call you to account for all your errors.