A diachronic development in Biblical Hebrew is studied by which the relative subordinating particle becomes also a verb-complement subordinator. It is argued that this development is internally motivated and is not the result of borrowing; and that the development is not the result of simple-minded analogy Rather, two natural mediating channels are discussed which, it is felt , are responsible for this syntactic change. It is also suggested that a similar development may have taken place in Aramaic and Akkadian.