When the Lord scattered Israel, He "hid" them "in the nethermost parts of the vineyard." (5: 14.) The word "hid" suggests the deliberate concealment of the people, their true origin, their blood relation to Jacob, their destiny to become part of the covenant Family of Israel, and their loss from the record of history and even their own memory of the earlier connections. The Lord of the vineyard intended for this part of His plan to remain concealed. He knew what He was doing. He was acting on a plan designed to produce preservable fruit, but mankind would be oblivious to His methods. His ways are not always shared or understood by man. (Isa. 55: 8-9.)
The places are not numbered, but described as "nethermost." Nor is the design identified other than "some in one and some in another, according to his will and pleasure." This is an order which He keeps to Himself, but we are told it reflects His "will" and His "pleasure."
The Lord left the vineyard to continue in the ordinary course "that a long time passed away." (5: 15.) There is no haste involved. Men come and go across generations while the design of God unfolds. We are impatient and want to see God's plan unfold completely within our lifetime here, but His work is ageless and spans generations. Rarely does He promise a single generation will witness promised events. (See, e.g., JS-M 1: 32-34.)
When a "long time" had passed away, the Lord no longer stood watch, but took His servant and "went down" to "labor in the vineyard." (5: 15.) His presence and ministry among men took a more direct effort. He "went down into the vineyard to labor" for the souls of men. Behold the condescension of God, indeed!
The underlying "root" was able to give "nourishment" to the hybrid people living when the Lord came. The surviving prophetic warnings and limited practices supported this new Dispensation, making it a field white, already to harvest. (5: 17-18.)
There He found among those grafted into the natural root disciples willing to follow Him. Among them were those who were "good" and "like unto the natural fruit"-- which would make them candidates to be adopted as sons and daughters of God, as the Family of Israel. The Lord rejoiced because He realized He could "lay up much fruit, which the tree thereof hath brought forth; and the fruit thereof I shall lay up against the season, unto mine own self." (5: 18.)
The Lord's personal ministry resulted in a great harvest of souls. There were many willing to accept His mission, respond to Him, and go through the process of changing into covenant Israel again. Sons and daughters of God returned to the earth by adoption into the Family of God. (See, e.g., Rom. 8: 16-17; Eph. 1: 5; 2: 19, 1 John 3: 2; among many others.)