‘ And it went down westward to the border of the Japhletites, to the border of Beth-horon the Lower, even to Gezer. And its goings out were at the sea.'
The Japhletites were another Canaanite family group prominent enough for their border to act as a border marker. The border then went on to lower Beth-horon (see Joshua 10:10-11), and then to Gezer, which is fifteen kilometres (nine miles) further west, and on to the Great Sea where the border inevitably changed course (‘its goings out' - see on Joshua 15:7).