The word of Samuel came to all Israel. Now Israel went out against the Philistines to battle, and encamped beside Ebenezer: and the Philistines encamped in Aphek.
"The ark of the covenant of the Lord"  (1 Samuel 4:3).  This, like countless other instances of the same phenomenon, indicates a complete familiarity on the part of the elders of Israel with the appearance and utility of the ark of the covenant as revealed in the Pentateuch.  The cherubim were symbolical representations of supernatural creatures adorning the top of the mercy seat located as a covering for the ark of the covenant; and the conception that God was "enthroned above the cherubim" was derived from the Mosaic revelation that the Presence of God Himself was associated with the ark of the covenant.  The ark of the covenant here is exactly the same as "the ark of God "mentioned in  1 Samuel 3:3.