Charles Spurgeon Commentary 1 Samuel 3:13

"For I have told him that I will judge his house for ever, for the iniquity which he knew, because his sons did bring a curse upon themselves, and he restrained them not." — 1 Samuel 3:13 (ASV)

Because his sons made themselves vile, and he restrained them not.

A man said to me, one day, "I never laid my hand upon my children;" and I answered, "Then I think it is very likely that God will lay his hand upon you." "Oh!" he said, "I have not even spoken sharply to them." "Then," I replied, "it is highly probable that God will speak very sharply to you; for it is not God's will that parents should leave their children unrestrained in their sin."