What does 1 Samuel 2:34 mean?

The Lord's prophetic judgment of Eli, the priest of Israel, reaches its painful climax. Eli was guilty, at least, of allowing his two boys to abuse their role as priests serving in the sanctuary. He confronted them at some point (1 Samuel 2:22–25), but he did not stop them (1 Samuel 3:13). In fact, the old priest seems to have benefitted from their demands of the choicest parts of the sacrifices for themselves (1 Samuel 2:12–17, 29).

Through an unnamed prophet, the Lord has revealed to Eli that all his future descendants will die young—perhaps even violently (1 Samuel 2:32–33). Since Eli will not himself live to see those days, the Lord promises to give Eli a sign to prove this will happen: both of Eli's sons, Hophni and Phinehas, will die on the same day. Such an unlikely tragedy would clearly be the confirmation that everything the Lord has predicted will happen.

This prophecy is later fulfilled when Eli's sons are killed in a battle with the Philistines and the ark of the covenant is captured (1 Samuel 4:10–18).