Although "Undeutsche Psalmen" was first published in 1587, researchers have concluded that most of the texts were either written in the first third of the 16th century or translated from Middle Low German in that same period. Therefore, these religious songs belong to the earliest tradition in the Latvian language and they can be very important for answering questions related to the history of Latvian language and literature. These songs are part of the translation literature, therefore they are also important for the translation theory.