Albert Barnes Commentary 1 Samuel 6:19

"And he smote of the men of Beth-shemesh, because they had looked into the ark of Jehovah, he smote of the people seventy men, [and] fifty thousand men; and the people mourned, because Jehovah had smitten the people with a great slaughter." — 1 Samuel 6:19 (ASV)

Fifty thousand and three score and ten - This should be read as "seventy," omitting the "fifty thousand," which appears to have crept into the text from the margin. It is not improbable that in their festive rejoicing, the priests, Levites, and people may have fallen into intemperance and therefore into presumptuous irreverence (compare Leviticus 10:1, 9).

God had just vindicated His own honor against the Philistines; it must now be seen that He would be sanctified in them that come near Him (Leviticus 10:3). It is clear to see how the doctrine of atonement, and its necessity for sinners, is taught in this and similar lessons about the awesome HOLINESS of God.