The fourfold recurrence of the root śkl in 1 Samuel 18 to describe David (vv. 5, 14, 15, 30) calls for an explanation. While David’s characterization as maśkîl would seem to refer, above all, to his success in battle, a broader analysis of śkl in wisdom-related contexts, as well as elsewhere in the Deuteronomistic History, demonstrates that maśkîl functions as an epithet, bestowing upon the holder a wider sense of “success” that is intimately linked with Divine patronage. Thus, David’s characterization as maśkîl in 1 Samuel 18 promotes a more comprehensive definition of the ideal king, in contrast to the more restricted prerequisite of military skill associated with Saul. While it is most likely that the story in 1 Samuel 18 is composed solely from pre-Deuteronomistic strands, the intensity with which the root śkl is employed with relation to David corresponds with the Deuteronomistic agenda of portraying David as the ideal king.
WeinfeldDeuteronomy and the Deuteronomic School p. 346views this expression as being rooted in wisdom literature. lĕmaʿan taśkîlû expresses the call to internalize the acts of God as a basis for observing the covenant (Deut 29:8; cf. Ps 64:10). See D. L. Christensen Deuteronomy 21:10-34:12 (wbc; Waco 2002) pp. 710-12.