Word study! The Mormon Church has their temples to utter secret oaths to their god. They will tell you they are sacred not secret, but they won’t tell you what those oaths are. That’s what makes them secret!
1 Nephi 20:16 even says that their god doesn’t speak in secret. “Come ye near unto me; I have not spoken in secret; from the beginning, from the time that it was declared have I spoken; and the Lord God, and his Spirit hath sent me”.