Albert Barnes Commentary 1 Samuel 4:1

"And the word of Samuel came to all Israel. Now Israel went out against the Philistines to battle, and encamped beside Eben-ezer: and the Philistines encamped in Aphek." — 1 Samuel 4:1 (ASV)

Some attach the opening words of the chapter to the end of 1 Samuel 3:21, as the complement to what is said there: The Lord revealed himself to Samuel ... in Shiloh, and the word of Samuel went forth to all Israel. If placed at the beginning of 1 Samuel 4 and connected with what follows, these words are to be understood as meaning that Samuel called all Israel to battle against the Philistines (compare to 1 Samuel 7:5). But this is not the natural interpretation of the words, which seem to belong to what came before.

The mention of the Philistines connects this narrative with Judges 13–16. The Philistine servitude lasted for forty years (Judges 13:1) and seems to have ended during Samuel's time (1 Samuel 7:13–14), around the twentieth year of his judgeship (1 Samuel 7:2). This servitude had already begun before the birth of Samson (Judges 13:5), and Samson judged Israel for twenty years in the days of the Philistines (Judges 15:20). Therefore, it seems to follow that the latter part of Eli’s judgeship and the early part of Samuel’s must have coincided with the lifetime of Samson.

Eben-ezer (or, the stone of help) is a name the place was later given by Samuel; see the cross-references. "Aphek," or the "fortress," was probably the same as the "Aphek" of Joshua 12:18. It would be toward the western frontier of Judah, not very far from Mizpeh of Benjamin, and near Shiloh (1 Samuel 4:4).