1,700 or 7,000 horsemen?
2 Samuel 8:4—”Did David capture 1,700 of King Zobah’s horsemen (2 Samuel 8:4), or was it 7,000 (1 Chronicles 18:4)?”
It is sufficiently clear that the original text for 2 Samuel 8:4 is seven thousand; (“one thousand chariots seven thousand horsemen”), like in Chronicles. When the word chariot (רכב) was accidentally omitted in an early scribal transcription, it left the awkward “one thousand seven thousand horsemen,” which must have motivated a later scribe to correct that to “one thousand seven hundred.”
It is worth noting that some of the most reliable ancient manuscripts actually still have the correct figure (7,000) in both verses; this scribal error didn’t affect all existent texts. For a fuller explanation of such minor scribal copyist mistakes in the Qur’ān and Bible, see the article on variants in the Qur’ān and Bible.