And it came to pass, when he made mention of the ark of God, that he fell from off the seat backward by the side of the gate, and his neck brake, and he died: for he was an old man, and heavy. And he had judged Israel forty years.

And it came to pass, when he made mention of the ark of God, that Eli feel from off his seat backward by the side of the gate; and his neck brake, and he died: for he was an old man, and heavy. And he had judged Israel forty years.

And when he had named the ark of God, he fell from his stool backwards by the door, and broke his neck, and died. For he was an old man, and far advanced in years: and he judged Israel forty years.

And it came to pass, when he mentioned the ark of God, that he fell from off the seat backward by the side of the gate, and his neck broke, and he died; for the man was old, and heavy. And he had judged Israel forty years.

And it cometh to pass, at his mentioning the ark of God, that he falleth from off the throne backward, by the side of the gate, and his neck is broken, and he dieth, for the man is old and heavy, and he hath judged Israel forty years.

And at these words about the ark of God, Eli, falling back off his seat by the side of the doorway into the town, came down on the earth so that his neck was broken and death overtook him, for he was an old man and of great weight. He had been judging Israel for forty years.

And when he had named the ark of God, he fell from the seat backwards, toward the door, and, having broken his neck, he died. For he was an old man of great age. And he judged Israel for forty years.

A comparison of 2-Samuel 18:4, explains exactly the meaning of the "side of the gate," and Eli's position. His seat or throne, without a back, stood with the side against the jamb of the gate, leaving the passage through the gate quite clear, but placed so that every one passing through the gate must pass in front of him.
Forty years - This chronological note connects this book with that of Judges. (Compare Judges 3:11, etc.) It is an interesting question, but one very difficult to answer how near to the death of Phinehas, the son of Eleazar the High Priest, Eli's forty years of judgeship bring him. It is probable that at least one high priesthood intervened.

When he made mention of the ark of God - Eli bore all the relation till the messenger came to this solemn word; he had trembled before for the ark, and now, hearing that it was captured, he was transfixed with grief, fell down from his seat, and dislocated his neck! Behold the judgments of God! But shall we say that this man, however remiss in the education of his children, and criminal in his indulgence towards his profligate sons, which arose more from the easiness of his disposition than from a desire to encourage vice, is gone to perdition? God forbid! No man ever died with such benevolent and religious feelings, and yet perished.
He had judged Israel forty years - Instead of forty years, the Septuagint has here εικοσι ετη, twenty years. All the other versions, as well as the Hebrew text, have forty years.

And it came to pass, when he made mention of the ark of God,.... Of the taking of that, it struck him to the heart, and killed him; the rest he bore tolerably well, the flight of Israel before the Philistines, the great slaughter made of them, the death of his two sons; but the taking of the ark was so dreadful to him, that he could not support under it:
that he fell from off the seat backward, by the side of the gate; which confirms the sense of 1-Samuel 4:13 though whether it was the gate of his own house, or of the tabernacle, or of the city is not certain; the latter is most probable: it seems the seat on which he sat had no back to it, and might be placed only for present convenience:
and his neck brake; the back part of it, the "vertebrae" of it, which has its name in Hebrew from the several joints in it:
and he died; not through the breaking of his neck, for it is very probable he died directly upon hearing the ark was taken, and which was the reason of his falling backward, and that brake his neck:
for he was an old man, and heavy; full of flesh, a very fat man, and so fell heavy, which occasioned the breaking of his neck:
and he had judged Israel forty years; had governed them in the capacity both of an high priest and judge, so that he must enter on his government when fifty eight years of age; the Septuagint version has it very wrongly twenty years. According to the Jews (i), he died on the tenth of Ijar, answering to part of April and May, and his two sons and the ark taken; for which a fast was kept on it.
(i) Schulchan Aruch, par. 1. c. 580. sect. 2.

He fell - Being so oppressed with grief and astonishment, that he had no strength left to support him. The gate - The gate of the city, which was most convenient for the speedy understanding of all occurrences. Old - Old, and therefore weak and apt to fall; heavy, and therefore his fall more dangerous. So fell the high - priest and judge of Israel! So fell his heavy head, when he had lived within two of an hundred years! So fell the crown from his head, when he had judged Israel forty years: thus did his sun set under a cloud. Thus was the wickedness of those sons of his, whom he had indulged, his ruin. Thus does God sometimes set marks of his displeasure on good men, that others may hear and fear. Yet we must observe, it was the loss of the ark that was his death, and not the slaughter of his sons. He says in effect, Let me fall with the ark! Who can live, when the ordinances of God are removed? Farewell all in this world, even Life itself, if the ark be gone!