Helaman 6:25

Now behold, it is these secret oaths and covenants, which Alma commanded his son should not go forth unto the world, lest they should be a means of bringing down the people unto destruction.

These were the secret promises that Alma told his son not to share with the world. He was afraid they would destroy the people.

These are the same secret oaths and covenants that Alma told his son never to reveal publicly, because they could destroy entire peoples.