Adam Clarke on 1 Samuel 4:1

The word of Samuel came to all Israel - This clause certainly belongs to the preceding chapter, and is so placed by the Vulgate, Septuagint, Syriac, and Arabic.

Pitched beside Eben-ezer - This name was not given to this place till more than twenty years after this battle, see 1Sam 7:12; for the monument called האבן העזר haeben haezer, the "Stone of Help," was erected by Samuel in the place which was afterwards from this circumstance, called Eben-ezer, when the Lord had given the Israelites a signal victory over the Philistines. It was situated in the tribe of Judah, between Mizpeh and Shen, and not far from the Aphek here mentioned. This is another proof that this book was compiled after the times and transactions which it records, and probably from memoranda which had been made by a contemporary writer.