Charles Ellicott Commentary 1 Samuel 2:34

"And this shall be the sign unto thee, that shall come upon thy two sons, on Hophni and Phinehas: in one day they shall die both of them." — 1 Samuel 2:34 (ASV)

In one day they shall die both of them. —See for a literal fulfillment the recital in 1 Samuel 4:11. This foreshadowing of terrible calamity which was to befall Israel was to be a sign to Eli that all the awful predictions concerning the fate of his doomed house would be carried out to the bitter end.