Albert Barnes Commentary Joshua 17:10

"southward it was Ephraim`s, and northward it was Manasseh`s, and the sea was his border; and they reached to Asher on the north, and to Issachar on the east." — Joshua 17:10 (ASV)

Southward — that is, of the river Kanah.

Render it as: they (that is, the two kindred tribes of Ephraim and Manasseh, the northern border being treated here as common to the two) reached to Asher. (See the map.) The northern border is only indicated in general terms, perhaps because the Israelites were not yet completely masters of this part of the country and so had not precisely determined it.