The Bible shows that a certain percentage of mankind will survive the Great Tribulation. It will be these people who survived the Great Tribulation, but who were not found in the First Resurrection, who the saints will rule over in the Millennium.
Isaiah 30:21 provides a glimpse of this future role: “And thine ears shall hear a word behind thee, saying, This is the way, walk ye in it, when ye turn to the right hand, and when ye turn to the left.”
During the Millennium, the saints or elect will literally speak to those who may not know Yahweh’s Word. Again, this would be those who survived the Great Tribulation, but who were not found worthy as saints in the First Resurrection.
Because the saints will be educating others in Yahweh’s ways, it only stands to reason that they would be obeying His laws today, especially His Sabbaths and Feasts, which will be mandated at this time. An example of this is found in Zechariah 14:16-19. There Scripture confirms that all nations will observe the Feast of Tabernacles and those who resist will receive the plague of drought. We see similar examples in Isaiah 66:23; Ezekiel 45:21-25; and 46:1-4.