Jarom 1:9

and thus being prepared to meet the Lamanites, they did not prosper against us. But the word of the Lord was verified, which he spake unto our fathers, saying, That inasmuch as ye will keep my commandments, ye shall prosper in the land.

Because we were ready to fight the Lamanites, they could not win against us. The Lord’s promise came true. He had told our fathers, “If you keep my commandments, you will succeed in this land.”

Because we were prepared, the Lamanites couldn’t defeat us. The Lord’s promise to our ancestors came true: ‘If you keep my commandments, you’ll thrive in the land.’