2 Samuel 21:19
18 Later there was another battle with the Philistines, this time in Gob. On that occasion Sibbekai the Hushathite killed Saph, who was one of the descendants of Rapha. 19 Yet another battle occurred with the Philistines in Gob. On that occasion Elhanan the son of Jair the Bethlehemite killed the brother of Goliath the Gittite, the shaft of whose spear was like a weaver’s beam. 20 Yet another battle occurred in Gath. On that occasion there was a large man who had six fingers on each hand and six toes on each foot, twenty-four in all! He too was a descendant of Rapha.
LXX 2 Samuel 21:19
18 And after this there was a battle again with the Philistines in Geth: then Sebocha the Astatothite slew Seph of the progeny of Rapha. 19 And there was a battle in Rom with the Philistines; and Eleanan son of Ariorgim the Bethleemite slew Goliath the Gittite; and the staff of his spear was as a weaver's beam. 20 And there was yet a battle in Geth: and there was a man of stature, and the fingers of his hands and the toes of his feet were six on each, four and twenty in number: and he also was born to Rapha.
Notes and References
"... What is unusual about the LXX translation to 1 Samuel 17-18 is the way in which the text was reworked: unlike the Masoretic text, it was not harmonized by means of explanatory additions; instead, it was boldly and thoroughly abridged. Although such a reworking might appear highly irregular, an examination of its components makes it quite understandable. Drastic interventions for the sake of harmonization are extant in the Book of Chronicles. 1 Chronicles 20:5 relates that Elhanan son of Ya‘or killed “Lahmi the brother of Goliath the Gittite”, thereby removing the contradiction between our story and the passage in 2 Samuel 21:19, which attributes the victory over Goliath to Elhanan of Ya‘re the Bethlehemite. And one by one, 1 Chronicles 21 does away with the three contradictions found in the story of the pestilence in 2 Samuel 24. First it deals with the duration of the plague, then the way in which it was halted, and finally the reason why Araunah’s threshing floor was consecrated as a place of worship.10 chronicles also shows examples of drastic abridgement: it omits the entire reign of Ish-boshet (2 Samuel 1-4) and the scandals at David’s court (2 Samuel 9-20), all in order to enhance David’s image. What is new about the shorter version of 1 Samuel 17-18 is neither that it was harmonized nor that it was abridged, but that here, the two processes went hand in hand: the harmonization was achieved by means of a comprehensive abridgement. This sort of phenomenon should not be considered a completely unreasonable freak occurrence in scripture, and we may safely reach the conclusion that the mt is closer to the original, whereas the shorter LXX version consists of a later abridgement. From all indications, what was abridged was a Hebrew text which later became the vorlage of the Greek translator ..."
Rofé, Alexander David Overcomes Goliath (1 Samuel 17): Genre, Text, Origin, and Message of the Story (pp. 66-100) Hebrew University of Jerusalem, 2015