The German text is from Gotter's play "Esther". It was probably first printed in 1795 (Leipzig), when W.A. and L. had long joined the Heavenly Choirs. The melody by the physician Bernhard Flies seems to be just a variant of an original by Friedrich Fleischmann. (The Wikipedia article has been written by the composer's descendants and thus may not be unbiased.)

Folk tradition changed the beginning of the lyrics for better rhythm: "Schlafe, mein Prinzchen, es ruhn / Schäfchen und Vögelein nun ...". For girls, "mein Prinzchen" is changed to "Prinzesschen".

Only the first stanza is common knowledge, my mum sang it at my cradle. Indeed, the sighing maid may not be the best idea to make a child sleep. (A genuine prince is not supposed to worry about maids, but will he know that when he's alone at night?)