Isaiah 27:6

God looked down and saw Israel drowning in her own blood and whispered… live.. live. Israel would take root spreading the seeds of the Word of God to the entire world through the disciples of Jesus Christ. Israel shall always be the apple of God’s eye. The Body of Christ, the Church, will be spotless in Jesus, sharing the Fruit of the Holy Spirit with all who come near.

Isaiah 27:6

Those who come He shall cause to take root in Jacob;

Israel shall blossom and bud,

And fill the face of the world with fruit.

³¹ And the remnant who have escaped of the house of Judah Shall again take root downward, And bear fruit upward. 

Isaiah 37:31

⁵ I will be like the dew to Israel; He shall grow like the lily, And lengthen his roots like Lebanon. 

Hosea 14:5

⁶ His branches shall spread; His beauty shall be like an olive tree, And his fragrance like Lebanon. 

Hosea 14:6

In this chapter the prophet goes on to show what great things God would do for his church and people, which should now shortly be accomplished in the deliverance of Jerusalem from Sennacherib and the destruction of the Assyrian army; but it is expressed generally, for the encouragement of the church in after ages, with reference to the power and prevalency of her enemies.

That he would greatly multiply and increase them (v. 6). 

All this is applicable to the grace of the gospel, and God's promises to, and providences concerning, the Christian church, and such as belong to it. 

excerpt from Matthew Henry’s Concise Commentary

Verse 6

Take root — To be firmly settled in their possessions.

Fruit — Their posterity shall seek habitations in other countries, and replenish them with people. But this seems to be understood of the spiritual seed of Jacob.

John Wesley

Verse 6. 

He shall cause them that come of Jacob to take root,.... That is, the posterity of Jacob, the seed of Israel, in a spiritual sense; such who are Israelites indeed, in whom there is no guile; these shall be so far from being plucked up, or rooted out of the vineyard, the church, that they shall take deeper root, and their roots shall spread yet more and more; they shall be rooted and grounded in the love of God, and also in Christ, and be built up in him, as well as firmly settled and established in the church, Ephesians 3:17 or, "them that come to Jacob {u}"; proselytes unto him, converted Gentiles, that come to the church of Christ, signified by "Jacob," and give up themselves unto it, and are added to it, these shall take root. The words may be rendered, in days "to come, he shall cause Jacob to take root": or, he "shall take root," as Aben Ezra, Jarchi, and Ben Melech supply the words; and so they are a prophecy of the stability and prosperous estate of the church in the latter day: Israel shall blossom and bud, and fill the face of the world with fruit; which may be understood of the fruits of grace and righteousness, which shall appear upon the people of God, in all parts of the world; or of the great number of converts everywhere; so the Targum, by "fruit," understands children's children; the sense is, that when the church of God, in the latter day, is settled and established, grounded in Christ, and in the doctrines of grace, it shall be in very flourishing and fruitful circumstances, abounding in grace and good works, and with numbers of converts; it shall be like the mustard tree, when it becomes so great a tree as that the birds of the air make their nests in it; and as the stone cut out of the mountain without hands, when it becomes a great mountain, and fills the whole earth, Matthew 13:31 compare with this Isaiah 37:31.

John Gill’s Exposition of the Bible