Jeremiah 31:6

New English Translation

⁶Yes, a time is coming
when watchmen^[a] will call out on the mountains of Ephraim,
“Come! Let us go to Zion
to worship the Lord our God!”’”^[b]

Jeremiah 31:6 sn Watchmen were stationed at vantage points to pass on warning of coming attack (Jer 6:17; Ezek 33:2, 6) or to spread the news of victory (Isa 52:8). Here reference is made to the watchmen who signaled the special times of the year, such as the new moon and festival times, when Israel was to go to Jerusalem to worship. Reference is not made to these in the Hebrew Bible, but there is a good deal of instruction regarding them in the later Babylonian Talmud.
Jeremiah 31:6 sn Not only will Israel and Judah be reunited under one ruler (cf. 23:5-6), but they will share a unified place and practice of worship once again, in contrast to Israel using the illicit places of worship, illicit priesthood, and illicit feasts instituted by Jeroboam (1 Kgs 12:26-31) and continued until the downfall of Samaria in 722 b.c.

New English Translation (NET)