This article addresses some key aspects of the relation between textual fluidity and rewriting in the Second temple period on the basis of the comparison between the David traditions in Samuel and in Chronicles. While the discovery of Sam manuscripts in Cave 4 of Khirbet Qumran (especially 4QSama) has made likely that Chr used a source distinct from Sam MT, recent debates about the character of 4QSama and literary revisions in Sam MT and LXX suggest that the fluidity of the David traditions at the time of Chr’s composition may in fact have been even more significant than previously assumed. Building on this, the article compares the rewriting of these David traditions in Sam and Chr; in particular, it argues that although the scope of such rewriting is usually much more significant in Chr, there are several passages where Chr preserves an account of David which is less expansionist than Sam MT, and sometimes even than any other ancient version of Sam, as already observed by S. L. McKenzie and others. The implications of this finding for the characterization of Chr as rewritten composition are explored in the last part of the article. Chr’s relation to Sam emerges as a paradigmatic – albeit by no means unique – example of the complex dynamics that unite a rewritten composition to its source; this finding questions any simple, straightforward relation between the development of rewritten compositions and the textual stabilization of the source(s) on which these compositions are based. Furthermore, while it is possible to understand what features, precisely, would have led the ancient audience of Chr to see that work as a new composition, rather than as a variant edition of its source, it is dubious that such features may be used to define a literary genre proper.