2 Samuel 21:19

“And there was again a battle in Gob with the Philistines, etc.] Another battle with them in the same place: where Elhanan the son of Jaareoregim, a Bethlehemite, slew [the brother of] Goliath the Gittite; the word “brother” is rightly supplied from (<132005>1 Chronicles 20:5); where his name is said to be Lahmi, for not Goliath himself was slain, though some so interpret it, and take Elhanan to be David; so Jarchi, and with which agrees the Targum; but he was slain not at Gob, but in the valley of Elah, nor had David any such name as Elhanan; he was one of David’s worthies, (<102324>2 Samuel 23:24); where he is called the son of Dodo, and in (<132005>1 Chronicles 20:5), the son of Jair; and…”

“The Hebrew text is manifestly very corrupt. First, for “Jaare-oregim,” 1 Chronicles 20:5 gives us the reading Jair. “Oregim” has evidently got in by a transcriber’s error from the line below, where “oregim” is the Hebrew for “weavers.” Again, the word the “Bethlehemite” is very doubtful. It is supported by 2 Samuel 23:24, but it is not found in the far purer text of 1 Chronicles 20:5, but instead of it we find the name of the Philistine slain by Elhanan, “Lahmi the brother of Goliath the Gittite.” It is probable, therefore, that either the words “the Bethlehemite,” are a corruption of “Lahmi,” or that the recurrence of “Lahmi,” and the termination of “Beth-lehemite” has confused the…”

“21:19 Some traditions identify Elhanan as David, principally because Elhanan was also from Bethlehem and because David killed Goliath (1 Sam 17:48-51). But it is more likely that the words brother of were omitted from the Masoretic Text by scribal error.”

“Elhanan: etc. Instead of את גלית יערי ארגיס בית הלחמי, of the text, we should certainly read, as in the parallel text, "and Elhanan the son of Jair, slew Lahmi the brother of Goliath." Ch1 11:26 Jaareoregim: or, Jair, Ch1 20:5 Goliath: Sa1 17:4-11 2 Kings (2 Samuel) 21:20”