Commenting on some textual difficulties and internal inconsistencies in 1 Sam 17, one Protestant commentator wrote:
1 Samuel 17.1-54
We must look briefly at the main difficulties of this story, mainly because they are so often insisted on in schools and colleges. They are: (a) if David had been Saul’s harper and armour-bearer, he would have had no difficulty in going direct to Saul (31); (b) vs. 33-36 are hardly compatible with 16.18; (c) ignorance of David’s identity (55-58) is hardly explicable; (d) David’s periodic return to the work of a shepherd (15) seems unnatural.
In the Greek (Codex Vaticanus) 17.12-31 and 17.55-18.5 are missing. If we could accept this as correct, the problem would largely vanish; but the translator probably omitted the verses just because he saw the difficulty. If on the other hand we assume that the story if earlier than that in 16.14-23, though probably after the anointing, then most (not all) of the difficulties vanish. We would have to see in v. 15 the effort of a late editor to explain an obvious problem. Another pointer to an earlier day for this story is the fact that no effort was made at the time to implement the promise that he should be Saul’s son-in-law; if he was merely a lad, he was too young for marriage . . . The reason why the two sides faced on another harmlessly for forty days (16) was because “the valley of Elah” (20 was little more than a ravine; anyone trying to cross it in the face of the enemy would be going to almost certain death. David could do it only because he was responding to Goliath’s challenge; by the rules of the contest he had to let him cross.
David expected a victory, not because he was an Israelite and Goliath a Philistine, but because he interpreted Goliath’s words as a challenge to God Himself (45-47). We must always be prepared to distinguish between our cause and God’s. They are not necessarily the same. But behind the confidence lay an assurance based on doing his duty. Whenever (better than “when” in v. 34) lion or bear interfered with his sheep, he dealt with them as a matter of course. We shall not do great things for God unless we learn to do the lesser as well. If God had looked after him while he did his duty, how much more when he was God’s champion?
“His tent” (54)—probably God’s tent, cf. 21.9. “To Jerusalem”: presumably David had the head picked and hung in his banqueting hall after he had captured Jerusalem. (H.L. Ellison In The Daily Commentary, vol. 1: Genesis-Job [London: Scripture Union, 1973], 258-59, emphasis in original)
The issue of the text of 1 Sam 16-17, particularly the narrative of David vs. Goliath, is a rather interesting one for Latter-day Saints; indeed, scholarship has shown that the narrative is composed of an early source (the “A”-source) and a later source (the “B”-source), as evidenced by the DSS, LXX, MT, and other considerations. Indeed, Nephi, in his narrative of his killing of Laban, employs the earlier A-source material, but never the later, post-exilic B-source, as an Old Testament template for the narrative.
LDS scholar Benjamin McGuire has written an excellent article on this topic, one which presents very strong evidence for the antiquity of the Book of Mormon:
