source of text

[Susan]

Does anyone have any information on the source of the text "Thou shalt know him when he comes?" The author is listed as anonymous...If this has been asked previously, I apologize. I am a new participant on this forum. Susan Onderdonk

[carlos]

Some sources state that it's a hymn composed by Hal H. Hopson, but I'm not sure if the lyrics were written by him too.