David took Metheg-ammah - This is variously translated. The Vulgate has, Tulit David fraenum tributi, David removed the bondage of the tribute, which the Israelites paid to the Philistines. Some think it means a fortress, city, or strong town; but no such place as Metheg-ammah is known. Probably the Vulgate is nearest the truth. The versions are all different. See the following comparison of the principal passages here collated with the parallel place in 1 Chr: -
2 Samuel 1 Chronicles
2Sa 8:1. - David took Metheg-ammah 2Sa 8:3. David 1Ch 18:1. - David took Gath and her towns. 1Ch 18:3. David
smote Hadadezer 2Sa 8:4. And David took from him smote Hadarezer 1Ch 18:4. And David took from him
1000 and 700 horsemen, and 20,000 foot. 1000 chariots, and 7000 horsemen, and 20,000 foot.
2Sa 8:6. Then David put garrisons in Syria 2Sa 8:8. And 1Ch 18:6. Then David put in Syria 1Ch 18:8. And
from Betah and Berothai cities of Hadadezer. 2Sa 8:9. from Tibhath and Chun cities of Hadarezer. 1Ch 18:9.
When Toi heard that David had smitten When Tou heard that David had smitten
Hadadezer 2Sa 8:10. Then Toi sent Joram his son Hadarezer 1Ch 18:10. He sent Hadoram his son
2Sa 8:12-Syria and Moab 2Sa 8:13. - Syrians, in the valley 1Ch 18:11-Edom and Moab 1Ch 18:12. - Edomites, in the valley
of salt, 18,000 2Sa 8:17. - Ahimelech - and Seraiah of salt, 18,000 1Ch 18:16. - Abimelech - and Shausha
was the scribe. 2Sa 10:16. Shobach the captain was scribe. 1Ch 19:16. Shophach the captain
2Sa 10:17. David passed over Jordan, and came הלאמה 1Ch 19:17. David passed over Jordan and came אלהם
to Helam. 2Sa 10:18. David slew 700 upon them 1Ch 19:18. David slew of the Syrians 7000
chariots of the Syrians, and 40,000 horsemen; chariots, and 40,000 footmen;