Mosiah 1:18

And now, it came to pass that Mosiah went and did as his father had commanded him, and proclaimed unto all the people which were in the land of Zarahemla, that thereby they might gather themselves together, to go up to the temple, to hear the words which his father should speak unto them.

Mosiah went and did what his father told him to do. He told all the people in the land of Zarahemla to come together and go to the temple to hear what his father would say to them.

Mosiah did exactly as his father commanded. He sent word to all the people in the land of Zarahemla to gather at the temple so they could hear what his father had to say to them.