Matthew Poole and continuators on Joshua 1:4

4 From the wilderness, and this Lebanon, even unto the great river, the river Euphrates, all the land of the Hittites, and unto the great sea , toward the going down of the sun, shall be your coast .

This emphatically, as being the most eminent Mountain in Syria, and the Northern border of the Land: or this which is within thy view; as if the Lord appeared to him in the form of a man, and pointed to it.

i. e. Of the Canaanites, who elsewhere are called Amorites; as Gen. 15. 16. and here Hittites by a Synecdoche: the Hittites being the most considerable and formidable of all, as may appear from Numb. 13. 33. and 14. 1. 2 King. 7. 6. and many of them being of the race of the Giants, dwelling about Hebron: See Gen. 25. 9, 10. and 26. 34. and 27. 46.

The Midland Sea, great in it self, and especially with those lesser Collections of waters, which the Iews called Seas.

Obj. The Israelites never possessed all this Land. Ans. 1. That was from their own sloth and cowardize, and disobedience to God, and breach of those Conditions upon which this Promise was suspended: See Iudg. 2. 20. 2. This Land was not all to be possessed by them at once, but by degrees, as their numbers and necessities increased; but Canaan being fully sufficient for them, and many of the Israelites being from time to time either cut off, or carried captive for their sins, there was never any need of enlarging their Possessions. 3. Though their Possessions extended not to Euphrates, yet their Dominion did, and all those Lands were tributary to them in David's and Solomon's time.

Marginal references: Exod. 23. 31. Numb. 34. 3.