Jeremiah 50:5

They shall ask the way to Zion with their faces thitherward,.... Either to Jerusalem, near to which Mount Zion was; or to the land of Israel, so called, from a principal part of it: and this also is not to be understood of their return thither, upon the taking of Babylon by Cyrus, and the liberty he gave them; for they had no need to inquire their way thither, nor do we find any where that they did; for though there might be many among them born in the captivity, who knew not the way; yet there were others that did, and could direct and go before them, even such who had seen the former temple, Ezra 3:12; but this suits better with the Jews in the latter day, upon the fall of mystical Babylon, when they shall be converted and return to their own land, and shall ask their way thither; being under a strong impulse of mind, and being bent upon it, and having full resolution to go thither: or else by Zion may be meant the church of God in Gospel times, as it often is; the way into which the converted Jews will ask, being deter mined to give up themselves to it, and become members of it; which way is not a religious education, mere morality, or a bare attendance on worship; but faith in Christ, and a profession of it, and submission to the ordinance of baptism;

[saying], come, and let us join ourselves unto the Lord in a perpetual covenant [that] shall not be forgotten; and then may they be said to "join [themselves] to the Lord", when, under a divine influence, they shall give up themselves to Christ, to be saved by him; when they shall lay hold on him, embrace him, and believe in him; when they shall follow him in his own ways, and cleave unto him with full purpose of heart; and also when they shall join themselves to his people, to the churches of Christ, and abide by his truths and ordinances; to all which they shall stir up and encourage one another; either laying hold on the covenant of grace, which is an everlasting one, and will never be forgotten by the Lord; he is ever mindful of it, and keeps it; which is done when men join themselves to the Lord, Isaiah 56:6; or making an agreement or covenant with one another, and the churches to which they join themselves, to walk together in all the ways, ordinances, and commandments of the Lord; which agreement or covenant ought to be perpetually observed, and never forgotten. Kimchi owns that this part of the verse belongs to the days of the Messiah. The Targum is,

"they shall come and be added unto the people of the Lord, and he shall make with them an everlasting covenant, which shall not cease.''