Jamieson, Fausset and Brown on Amos 6:14

14. from the entering in of Hamath--the point of entrance for an invading army (as Assyria) into Israel from the north; specified here, as Hamath had been just before subjugated by Jeroboam II (Am 6:2). Do not glory in your recently acquired city, for it shall be the starting-point for the foe to afflict you. How sad the contrast to the feast of Solomon attended by a congregation from this same Hamath, the most northern boundary of Israel, to the Nile, the river of Egypt, the most southern boundary!

unto the river of the wilderness--that is, to Kedron, which empties itself into the north bay of the Dead Sea below Jericho (2Ch 28:15), the southern boundary of the ten tribes (2Ki 14:25, "from the entering of Hamath unto the sea of the plain") [Maurer]. To the river Nile, which skirts the Arabian wilderness and separates Egypt from Canaan [Grotius]. If this verse includes Judah, as well as Israel (compare Am 6:1, "Zion" and "Samaria"), Grotius' view is correct; and it agrees with 1Ki 8:65.