And they who are far off shall come - They who came from Babylon with offerings to God, became types of the Gentiles, of whom the Apostle says, “Now in Christ Jesus ye who sometimes were far off have become nigh through the blood of Christ” Ephesians 2:13; and, “He came and preached peace to you which were far off and to them that were nigh” Ephesians 2:17; and “the promise is to you and to your children, and to all that are far off, as many as the Lord our God shall call” Acts 2:39.
And build in - or upon, the temple of the Lord (Nehemiah 4:4, Nehemiah 4:11 (Nehemiah 4:10, Nehemiah 4:17 in English).) Not “build it” for it was to be built by “the Branch,” but “build on,” labor on, it. It was a building, which should continually be enlarged; of which Paul says, “I, as a wise master-builder, according to the grace given unto me, laid the foundation, and another buildeth thereon; let every man take heed how, he buildeth thereupon” 1 Corinthians 3:10. Cyril: “What shall they build? Themselves, compacting themselves with the saints, and joining together in faith to oneness with those of Israel, Jesus Christ Himself being the head cornerstone and uniting together in harmony through Himself, what was of old divided. For He united “the two peoples into one new man, making peace, and reconciling in His own body all things unto the Father” Ephesians 2:15-16, which being accomplished, we shall own the truth of the holy prophets, and know clearly that it was God who spake in them and declared to us beforehand the mystery of Christ.”
And this shall be - Not as though the coming of Christ depended upon their faithfulness, but their share in it. “Ye shall know (he had said) that the Lord of hosts hath sent me unto you;” but whether this knowledge should reach to individuals, depends upon their obedience and their willingness to know; “it shall be, , if ye will diligently obey the voice of the Lord your God. For none of the wicked,” Daniel says, “shall understand” Daniel 12:10; and Hosea, “Who is wise, and he shall understand these things? prudent, and he shall know them? For the ways of the Lord are right, and the just shall walk in them and the transgressors shall stumble at them” ; and the wise man, “he that keepeth the law of the Lord getteth the understanding thereof” (Ecclesiasticus 21:11). So our Lord said, “If any man will do His will, he shall know of the doctrine, whether it be of God or whether I speak of Myself” John 7:17; “He that is of God heareth God’s words: ye therefore hear them not because ye are not of God: John 8:47 : Everyone that is of the truth heareth My voice” John 18:37. Osorius: “Because he had said, And ye shall know that the Lord hath sent me unto you, he warns them, that the fruit of that coming will reach to those only, who should hear God and with ardent mind join themselves to His name. For as many as believed in Him were made sons of God; but the rest were cast into outer darkness. But they receive Christ, who hear His voice and do not refuse His rule. For He was made the cause of eternal salvation to tell who obey Him.”