Albert Barnes Commentary 2 Samuel 21:19

"And there was again war with the Philistines at Gob; and Elhanan the son of Jaareoregim the Beth-lehemite slew Goliath the Gittite, the staff of whose spear was like a weaver`s beam." — 2 Samuel 21:19 (ASV)

The Hebrew text here is clearly very corrupt. For instance, instead of “Jaare-oregim,” the parallel account in 1 Chronicles 20:5 reads “Jair.” The word “Oregim” was evidently inserted by a transcriber’s error from the line below, where “oregim” is the Hebrew word for “weavers.”

Furthermore, the term “the Bethlehemite” is highly doubtful. While it is supported by 2 Samuel 23:24, it is absent from the much purer text of 1 Chronicles 20:5. Instead, the Chronicles passage gives the name of the man Elhanan killed as “Lahmi the brother of Goliath the Gittite.”

It is probable, therefore, that one of two errors occurred. Either the words “the Bethlehemite” are a corruption of the name “Lahmi,” or the similar sounds of “Lahmi” and the ending of “Beth-lehemite” confused the scribe, leading to the omission of one of the words in each respective text.