The number 800,000 appears in the Bible as the count of fighting men in Israel during David's census (2 Sam 24:9) and as the size of Jeroboam's army in the war against Abijah (2 Chron 13:3).
In 2 Samuel 24:9 it is reported that Joab counted 800,000 able-bodied men in Israel after David's census. This census was regarded as a serious sin because it expressed human pride and lack of trust in God, and it led to divine punishment in the form of a plague over the land. The episode illustrates the dangers of relying on military strength rather than divine providence. In 2 Chronicles 13:3 the same number appears as the size of Jeroboam's army force – 800,000 chosen warriors – when he went to war against Judah's king Abijah. Despite his enormous numerical advantage, Jeroboam suffered a crushing defeat, which again underscores the recurring biblical theme that military superiority does not determine the outcome when God intervenes. There is a numerical discrepancy between 2 Sam 24:9, which gives 800,000 fighting men in Israel, and 1 Chron 21:5, which gives 1,100,000. The difference has been the subject of extensive discussion among biblical scholars and may be due to different counting criteria, different sources, or copyist errors in the transmission of the text. According to rabbinic tradition, David's sin in the census was linked to the prohibition in Exod 30:12 against counting the people of Israel directly. The count was to be done indirectly, for example by collecting a half-shekel per person, to avoid treating people as mere statistics.*