Mosiah 21:32

And now since the coming of Ammon, king Limhi had also entered into a covenant with God, and also many of his people, to serve him, and keep his commandments.

Since Ammon came, King Limhi had also made a promise with God. Many of his people also promised to serve God and keep his commandments.

After Ammon arrived, King Limhi also made a covenant with God, along with many of his people, to serve him and keep his commandments.