The critical function of "canon"

Certainly earlier stages in the development of the biblical tradition were often regarded as canonical prior to the establishment of the final form. In fact, the final form frequently consists of an earlier, received form of the tradition which has been transmitted unchanged from its original setting. But to take canon seriously is also to take seriously the critical function which it exercises in respect to the earlier stages of the literature's formation. A critical judgment is exercised in the way in which the earlier stages are handled. At times the material is passed on, complete with all of its original historical particularity. At other times the canonical process selects, rearranges, or expands the received traditions. The purpose of insisting on the authority of the final form is to preserve the canon's role of providing this critical norm. To work with the final stage of the text is not to lose the historical dimension, but rather it is to provide a critical theological judgment regarding the process. A reconstructed depth dimension may aid in understanding the interpreted text, but it does not possess an inde-dependent integrity for the exegetical task within the context of the canon.

B.S. Childs, "The Canonical Shape of the Prophetic Literature," 1978: 48.