Jeremiah 31:7 - Matthew Poole's English Annotations on the Holy Bible

This grave, authoritative preface, Thus saith the Lord, seemeth to be prefixed to put the people of God out of fear of the accomplishment of the good things he had before promised and prophesied of. The verse in itself is either an exhortation to those amongst the Jews who feared God, or to the heathen, to sing and rejoice on the behalf of the Jews, to whom God would certainly show such mercy as they might sing for; before they had it in their hands, they might both publish the thing that it should certainly be, and also bless God for it. But withal he minds them that there would be occasion for prayer as well as praise, there would be a remnant of Israel that would have at least no present share in these mercies, through their impenitency, unbelief, and hardness of heart. Hereby minding us that we ought not so to rejoice in our good things, as to forget those who are no sharers with us. The best of God's people's lot, while they are in this life, is such as will show them a need of prayer as well as praise.