Ether 8:14

And it came to pass that they all sware unto him, by the God of Heaven, and also by the Heavens, and also by the earth, and by their heads, that whoso should vary from the assistance which Akish desired, should lose his head; and whoso should divulge whatsoever thing Akish made known unto them, the same should lose his life.

They all made a promise to him. They promised by God in Heaven, by the sky, by the earth, and by their own heads. They said that anyone who didn’t help Akish would lose his head. And anyone who told Akish’s secrets would lose his life.

They all took an oath—swearing by the God of Heaven, by the heavens themselves, by the earth, and by their own heads—that anyone who refused to help Akish would lose his head, and anyone who revealed what Akish told them would lose his life.