Jeremiah 31:6,7

For there shall be a day, that the watchmen shall cry By the watchmen are meant God's prophets, or the ministers of his word, giving notice of his dispensations, and calling upon men to act suitably under them. The first reference may be to the leaders and teachers of the Jews, returning from Babylon, or to the general summons throughout all the ten tribes, for which Ephraim is put, to repair to Jerusalem, and join themselves to the true church, from which they had been so long separated; but, doubtless, in the full completion of the prophecy, by watchmen the preachers of the gospel are to be understood. The phrase, crying upon mount Ephraim, alludes to the custom of persons that had to publish any proclamation ascending to the top of some high hill, from whence their voice might be heard a great way off. See Judges 9:7; 2 Chronicles 13:4; Isaiah 40:9. The phrase, Arise ye, let us go up to Zion, &c, alludes to the Jewish custom of going in companies to Jerusalem at their three annual festivals. For thus saith the Lord, Sing with gladness, &c. When ye see some dawning of these blessed times, express your joy for the restoration of Jacob's posterity in the most public manner that can be; and shout among the chief of the nations Namely, among the most potent nations from whence you are to be gathered. Or, persons belonging to the chief nations of the earth are here called upon to congratulate the Israelites on their restoration to their own land, and their conversion to the church of God, as Moses predicted, Deuteronomy 32:43, and the apostle exhorts, Romans 15:10, Rejoice, ye Gentiles, with his people; for when the promises made to the fathers are accomplished, the Gentiles shall glorify God for his mercy; as it is written, For this cause will I confess to thee among the Gentiles, and sing unto thy name, Romans 15:8. Publish ye, praise ye, and say, O Lord, save thy people Publish these good tidings with the highest expressions of praise and glory to God; and likewise pray that he, who hath begun so glorious a work, would proceed and complete it.