2 Samuel 1:18 New English Translation

¹⁸(He gave instructions that the people of Judah should be taught “The Bow.”^[a] Indeed, it is written down in the Scroll of the Upright One.)^[b]

2 Samuel 1:18 tn Heb “be taught the bow.” The reference to “the bow” is very difficult here. Some interpreters (e.g., S. R. Driver, P. K. McCarter, Jr.) suggest deleting the word from the text (cf. NAB, TEV), but there does not seem to be sufficient evidence for doing so. Others (cf. KJV) understand the reference to be elliptical, meaning “the use of the bow.” The verse would then imply that with the deaths of Saul and Jonathan having occurred, a period of trying warfare is about to begin, requiring adequate preparation for war on the part of the younger generation. Various other views may also be found in the secondary literature. However, it seems best to understand the word here to be a reference to the name of a song (i.e., “The Bow”), most likely the poem that follows in vv. 19-27 (cf. ASV, NASB, NRSV, CEV, NLT); NIV “this lament of the bow.”
2 Samuel 1:18 sn The Scroll of the Upright One (or The Book of Yashar) is a noncanonical writing which has not been preserved. Mentioned here and in Josh 10:12-13, it apparently was “a collection of ancient national poetry” (so BDB 449 s.v. יָשָׁר).

New English Translation (NET)