**Quelle** is a German word meaning "source" or "origin," commonly used in both everyday language and academic contexts. In biblical scholarship, "Quelle" refers specifically to the hypothetical "Q source" (from the German *Quelle*), which scholars believe was a written collection of Jesus’ sayings. This source is thought to have been used in the composition of the Gospels of Matthew and Luke, explaining the material they share that is not found in the Gospel of Mark.
Outside theology, *Quelle* was also the name of a major German mail-order and retail company, founded in 1927. It became one of Europe’s largest mail-order businesses before declaring bankruptcy in 2009. The term "Quelle" thus carries different meanings depending on the context—ranging from scholarly to commercial. In all uses, however, it emphasizes the idea of origin, whether it be a source of knowledge, historical information, or consumer goods.