Therefore say thou - Literally, "And thou sayest," that is, this having been so, it follows that thou sayest or must say, "Turn ye unto Me." In some degree they had turned to God, for whose sake they had returned to their land; and again when, after some negligence Haggai 1:2-11, they renewed the building of the temple, and God had said, "I am with you" Haggai 1:13. But there needed yet a more inward, more complete turning, whereon God promises a yet nearer presence, as Malachi repeats the words Malachi 3:7, and James exhorts, "Draw nigh to God and He will draw nigh to you" James 4:8. Those who have turned to God need ever to turn more into the center of the narrow way. As the soul opens itself more to God, God, whose communication of Himself is ever hindered only by our closing the door of our hearts against Him, enters more into it. "If a man love Me, he will keep My words, and My Father will love him, and We will come unto him, and make Our abode with him" John 14:23.
Osorius: "People are said to be converted, when leaving behind them deceitful goods, they give their whole mind to God, bestowing no less pains and zeal on divine things than before on the nothings of life."
Conc. Trid. Sess. vi. c. 5: "When it is said in Holy Scripture, "Turn unto Me and I will turn unto you," we are admonished as to our own freedom; when we answer, "Turn us, Lord, unto Thee, and we shall be turned," we confess that we are forecome by the grace of God."

Turn ye unto me - This shows that they had power to return, if they would but use it.
And I will turn unto you - I will show you mercy and grant you salvation, if you will use the grace I have already given you. Men are lost, because they turn not unto God; but no man is lost because he had not power to return. God gives this, and he will require it.

Therefore say thou unto them, Thus saith the LORD of hosts; (d) Turn ye unto me, saith the LORD of hosts, and I will turn unto you, saith the LORD of hosts.
(d) Let your fruits declare that you are God's people, and that he has wrought in you by his Spirit, and mortified you: for otherwise man has no power to return to God, but God must convert him; (Jeremiah 31:18; Lamentations 5:21) See Isaiah 31:6

Therefore say thou unto them,.... This is an order from the Lord to Zechariah, to say unto them, in the name of the Lord:
thus saith the Lord of hosts; of the hosts above and below, of angels and of men, of heaven and earth, and all that is therein: this is said, that the greater regard might be had to his words:
turn ye unto me, saith the Lord of hosts; by repentance, and acknowledgment of former sins; by reformation for the future; by attending to the worship and service of God, and seeking to glorify him. So the Targum, "return to my worship": this is not the condition of what follows, but what follows is the motive and encouragement to this:
and I will turn unto you, saith the Lord of hosts; to dwell among them, manifest himself unto and protect them. Three times the phrase, "the Lord of hosts", is used in this verse: it may be with respect to the three Persons in the Godhead, Father, Son, and Spirit; who manifest themselves unto, and take up their abode with, such as love the Lord, and keep his commandments; see John 14:21.

saith the Lord of hosts--a phrase frequent in Haggai and Zechariah, implying God's boundless resources and universal power, so as to inspire the Jews with confidence to work.
Turn ye unto me . . . and I will turn--that is, and then, as the sure consequence, "I will turn unto you" (Malachi 3:7; James 4:8; compare also Jeremiah 3:12; Ezekiel 18:30; Micah 7:19). Though God hath brought you back from captivity, yet this state will not last long unless ye are really converted. God has heavier scourges ready, and has begun to give symptoms of displeasure [CALVIN]. (Haggai 1:6).