Why does it say "Yesh Yom"?
Radak: There will be a time (not specifically a day). This is like "ba'Yom ha'Hu Shoresh Yishai" (Yeshayah 11:6) and similar verses.
Radak citing Targum Yonasan: There is length of days [and much good that will be give to Tzadikim].
Malbim: Initially, [Malchei Yisrael] set up guards in Har Efrayim to stop Yisrael from ascending to Yerushalayim. A day will come when guards will call and tell people to ascend to Tziyon! They will [not redeem their Revai, rather,] bring their Revai fruits to eat them in Yerushalayim!
Who are "Notzrim"?
Rashi #1: They are lookouts on top of tall towers to announce what is heard from afar.
Rashi #2: This is like "Notzer Chesed la'Alafim" (Shemos 34:7). It is an expression of guarding. I.e. there will be a day when they will call those who guarded Torah, and say "get up
