John Gill Commentary Joshua 17:9

"And the border went down unto the brook of Kanah, southward of the brook: these cities belonged to Ephraim among the cities of Manasseh: and the border of Manasseh was on the north side of the brook, and the goings out thereof were at the sea:" — Joshua 17:9 (ASV)

And the coast descended unto the river Kanah, southward of the
river
The same mentioned in the account of the coast of Ephraim, (Joshua 16:8) ; which was north of that river, as Manasseh was to the south of it:

these cities of Ephraim [are] among the cities of Manasseh ;
that is, the cities before mentioned, Asher, Michmethah, Entappuah, and Tappuah; though they were in the tribe of Manasseh, yet they were inhabited by the Ephraimites:

the coast of Manasseh also [was] on the north side of the river ;
of the river Kanah, as well as on the south of it; it had cities there, though possessed by the tribe of Ephraim:

and the outgoings of it were at the sea ;
the Mediterranean sea.