Here's the WTS explanation for Mt 8:11
*** it-1 p. 1247 Jacob ***
Jesus, on one occasion, used the name Jacob figuratively when speaking of those who would be “in the kingdom of the heavens.”—Mt 8:11.
*** w62 3/15 pp. 191-192 Questions From Readers ***
How can Matthew 8:11, which speaks of Abraham, Isaac and Jacob in the kingdom of the heavens, be harmonized with Matthew 11:11, which indicates that not even John the Baptist will be in it?
In Hebrews 11:8-19 we read: “By faith Abraham . . . dwelt in tents with Isaac and Jacob, the heirs with him of the very same promise. For he was awaiting the city having real foundations, the builder and creator of which city is God. . . . But now they are reaching out for a better place, that is, one belonging to heaven. Hence God is not ashamed of them, to be called upon as their God, for he has made a city ready for them. By faith Abraham, when he was tested, as good as offered up Isaac . . . But he reckoned that God was able to raise him up even from the dead; and from there he did receive him also in an illustrative way.”
How did Abraham expect to receive Isaac back from the dead? In heaven as a spirit? No, but here on earth as a human creature. In an illustrative way he got Isaac back from the dead here on earth. So Abraham was not looking for any spiritual, heavenly resurrection to put him among the celestial angels any more than he was expecting Isaac to have such a resurrection and rejoin him in heaven.
Abraham had come out of Ur of the Chaldeans, and he did not want that city any more. He and his son Isaac and grandson Jacob wanted a better place, that is, one belonging to heaven, a city government, namely, the government or city that God has prepared and in which the promised Seed or Offspring of Abraham will be God’s King. This is the “kingdom of God,” or “the kingdom of the heavens,” as these two expressions are interchangeable, the expression “the heavens” having reference to God. Under that kingdom of the heavens or kingdom of God Abraham, Isaac and Jacob expected to live on earth.
In the year 30 (A.D.) Jesus told Nicodemus that Abraham, Isaac and Jacob were not in heaven. (John 3:13) Three years later, on the day of Pentecost of the year 33, the apostle Peter said that the descendant of Abraham, Isaac and Jacob, namely, King David, had not ascended to heaven and so was not in any kingdom of the heavens or kingdom of God. (Acts 2:34) Peter said that after Jesus made the statement about Abraham, Isaac and Jacob in Matthew 8:11 at the time of healing the servant of a Roman centurion.
Hence those three patriarchs could not be in the Kingdom class as joint heirs with the Lord Jesus Christ. They were his ancestors, who preceded him by more than seventeen hundred years.
It is therefore evident that in Matthew 8:11 Jesus referred to Abraham, Isaac and Jacob figuratively. On the occasion when Abraham offered up his son Isaac, Abraham represented Jehovah God and Isaac represented God’s only-begotten Son Jesus Christ, who was offered up in sacrifice. Accordingly Jacob represented the spiritual Christian congregation, the “kingdom of the heavens” class; for, just as the congregation gets life through Jesus Christ, so Jacob got life from Abraham through Isaac. From this standpoint Abraham, Isaac and Jacob mentioned together in Jesus’ illustration would picture the great theocratic government, in which Jehovah is the Great Theocrat, Jesus Christ is his anointed representative King, and the faithful, victorious Christian congregation of 144,000 members is the body of Christ’s joint heirs in the Kingdom.
When the Christian congregation was founded on the day of Pentecost, its spirit-anointed members were made Christ’s joint heirs and were put in line for a place in the heavenly kingdom, to recline there at the spiritual table with the Greater Abraham and the Greater Isaac. The natural or fleshly Jews of the nation of Israel claimed to be the “sons of the kingdom” or the prospective members of God’s kingdom. From the day of Pentecost forward they saw the beginning and the gradual development of this theocratic arrangement, but because of their lack of faith in Christ they were not in it. Hence, as Jesus said (Matt. 8:12): “The sons of the kingdom will be thrown into the darkness outside. There is where their weeping and the gnashing of their teeth will be.”
For this reason it became necessary that many Gentiles (non-Jews), like the Roman centurion whose faith brought a miraculous cure by Jesus, should come “from eastern parts and western parts,” from all around the earth, to become dedicated, baptized Christians. Thus they could help make up the full number of the Kingdom class. For faithfulness to the death these converted Gentiles are resurrected to heavenly life to recline at the heavenly table, as it were, with Jehovah God and Jesus Christ “in the kingdom of the heavens.”
When understood this way, Matthew 8:11 agrees with Jesus’ words in Matthew 11:11: “Among those born of women there has not been raised up a greater than John the Baptist; but a person that is a lesser one in the kingdom of the heavens is greater than he is.” Since Abraham, Isaac and Jacob are not greater than John, they will not be literally in the kingdom of the heavens. Jesus used them only as an illustration of those who will actually be in it.