Alma 5:45

And this is not all. Do ye suppose that I know not of these things myself? Behold, I testify unto you, that I do know that these things whereof I have spoken, are true. And how do ye suppose that I know of their surety?

That is not all. Do you think I don’t know these things myself? I tell you that I do know that these things I have spoken are true. How do you think I know they are true?

And that’s not all. Do you think I don’t know these things for myself? I testify to you that I do know the things I’ve spoken about are true. How do you suppose I know they’re true?