The way I look at the sons of Jacob is figuratively according to the parable of the prodigal son who took his inheritance and went off to a far country and plundered it all. The youngest son is also figurative for a son who is not very matured in faith and so is little in faith and so he no longer relies on the faith of his Father (God), who sowed the seed of promise Jesus Christ and therefore went about doing his own thing in the diaspora of the world, thinking that he can make it on his own without the Father (God) of his fathers (Jacobs sons of the old covenant).
The youngest son then finds a drought where he can not sustain his identity and his worth and if he continues to stay the way he is, with the unclean things of the world, which symbolises the pig pen of the world. Then when he realises that he needs to go back to his Father (God), he has to come back completely broken and demoralised to no longer boast, but ask that he only be considered as a servant and not a son. The eldest son at this point is the one who is the one matured in faith, because he was always with the father, meaning he continued in the faith in Christ once delivered onto the saints (Jews). So this eldest brother in faith becomes someone jealous of his youngest rebellious brother, because the Father (God) is taking him back and is throwing a party for him by the slaughter of the fatted calf, which symbolises of the red heffer, which points to the sons of Jacob coming back to faith in droves after they realise that messiah has already come and that he is Jesus.
So Jesus also points to another parable of the workmen, from the 1st, 3rd, 6th, 9th and 11th. The 11th hour workmen come along towards the end of the new covenant age where they have only one hour to labour before the bride groom comes at 12:00 o'clock. So the 3rd, 6th and the 9th hour workmen become jealous when they get the same amount of treatment as the the last hour workmen. Couple this with the eldest in faith jealous brother in the prodigal son parable and what you have is the scenario that the youngest brother was deemed to have left the faith of the fathers (old covenant) from when the eldest son who is symbolised by the 3rd, 6th and 9th hour workmen stayed with the faith and laboured in the heat of the day by spreading the gospel, all the way to the final hour before 12 o'clock, where the bride groom was soon to come.
So this eldest brother who took the faith from the beginning when messiah came is the symbol of the gentile nations who ultimately carried it whilst the youngest son was disbanded until the fullness of these Gentiles comes where all the gentile world has been invited to come and what is left is the youngest son (Jacobs seed) to also come to the wedding supper of the lamb.
The youngest son's disbanding of the Abrahmic faith from the 1st century's ejection of messiah is also indicated in scripture as follows
Matthew 22
The Parable of the Wedding Banquet
1Jesus spoke to them again in parables, saying:
2“The kingdom of heaven is like a king who prepared a wedding banquet for his son.
3He sent his servants to those who had been invited to the banquet to tell them to come, but they refused to come.
4“Then he sent some more servants and said, ‘
Tell those who have been invited that I have prepared my dinner: My oxen and fattened cattle have been butchered, and everything is ready. Come to the wedding banquet.’
5“But they paid no attention and went off—one to his field, another to his business. 6The rest seized his servants, mistreated them and killed them. 7The king was enraged. He sent his army and destroyed those murderers and burned their city.
8“Then he said to his servants, ‘The wedding banquet is ready, but those I invited did not deserve to come.
9So go to the street corners and invite to the banquet anyone you find.’
10So the servants went out into the streets and gathered all the people they could find, the bad as well as the good, and the wedding hall was filled with guests.
11“But when the king came in to see the guests, he noticed a man there who was not wearing wedding clothes.
12He asked, ‘How did you get in here without wedding clothes, friend?’ The man was speechless.
13“Then the king told the attendants, ‘Tie him hand and foot, and throw him outside, into the darkness, where there will be weeping and gnashing of teeth.’
14“For many are invited, but few are chosen.”
Notice on the versus above the fattened cow is mentioned where the Father slaughters in celebrating his youngest son return and it is linked in context to the invitation to the wedding supper of the lamb which is an evangelistic calling as the 11th hour workmen, only if those who accept it can be clothed in time and to be made ready (oil in their lamps) for the bridegroom return, when he comes at 12 o'clock.
Notice also the context of the above verse
Tell those who have been invited that I have prepared my dinner is pointing squarely at the Jews (sons of Jacob). Yet they ignored the evangelistic calling and went about in the far country to waste their inheritance in the pig pen of the world. Then you see the Pharisees rebel against God to persecute the 1st century Jewish apostolic church and the result was the burning down of their city (Jerusalem) by the Romans in 70AD.
Jesus hints at the youngest son returning to the Abrahamic fathers faith when he states that the first (Jacobs seed) to hear about the gospel in the 1st century will become the last to embrace it and preach it for the last and final rally to preach it before 12 o'clock. What needs to happen is for Jacobs seed to say blessed is the Christ who came in the name of the Lord. This rally call will be paralleled to the rally that Gideon made with the Israelites when he said I want you to make a decision today. Will you accept the God of Israel, it so, then give me an answer today by saying yes.
The instrument that Jesus also hinted at is symbolised as God's handy work, the Assyrians (Men of Nineveh) will also be used by God to re-establish the highway and to post the invitation and to also rally behind Jacobs seed like the Gideon's of the world. Jesus would hint at this by saying the Men of Nineveh will come to chasten this generation because they believed in Jonah and yet there is one greater than Jonah standing and they believed not. So the Assyrians again will be like the symbol of the Jonah's of the world.
In conclusion the sons of Jacob will come and it is only a matter of time. The instrument of God's handy work, the Assyrians will be used to bring about this last hour rally. Then the gentile world (symbol of the eldest brother), seeing this will all come also in unity as one body and under one shepherd Jesus Christ, before the devil steps in to spoil the party and commit world wide Calvary in an unprecedented scale that pales the 1st century persecution of the Jewish apostolic church.
The ministry of the Power and Spirit of Elijah (God) will be from the church for the East where East is the symbol of the Sun/Son of righteousness who will speak through the mouth of one to bring back this youngest son back to his loving arms.
