Albert Barnes Commentary Isaiah 27:6

"In days to come shall Jacob take root; Israel shall blossom and bud; and they shall fill the face of the world with fruit." — Isaiah 27:6 (ASV)

He shall cause them that come of Jacob to take root - This language is derived from the vine, as the shoots or cuttings of the vine take root and flourish. To take root, therefore, is an emblem denoting that the descendants of Jacob, or the people of God, would increase and prosper.

Shall blossom and bud - An image also taken from the vine, or from fruit trees in general, and meaning that they should greatly flourish in the time following their return from the captivity.

And fill the face of the world with fruit - For the meaning of the word ‘face,’ see the note on Isaiah 25:7. The meaning is that the people of God would so increase and flourish that the true religion would ultimately fill the entire world.

The same idea of the universal prevalence of the true religion is often advanced by this prophet and occurs in various parts of the hymns or songs we are now considering . The figure which is used here, drawn from the vine, denoting prosperity by its increase and its fruit, is beautifully employed in Psalms 92:13-14:

Those that be planted in the house of Yahweh,
Shall flourish in the courts of our God.
They shall still bring forth fruit in old age;
They shall be rich and green.