Though he be fruitful among his brethren, an east wind shall come, the wind of the LORD shall come up from the wilderness, and his spring shall become dry, and his fountain shall be dried up: he shall spoil the treasure of all pleasant vessels.
Though he be fruitful - referring to the meaning of "Ephraim," from a Hebrew root 'to be fruitful' (Genesis 41:52). It was long the most numerous and flourishing of the tribes (Genesis 48:19, "His (Manasseh's) younger brother (Ephraim) shall be greater than he, and his seed shall become a multitude of nations").
An east wind shall come, the wind of the Lord i:e., sent by the Lord (cf. Isaiah 40:7), who has His instrument of punishment always ready. The Assyrian, Shalmaneser, etc., is meant (Jeremiah 4:11; Jeremiah 18:17; Ezekiel 19:12).
Shall come up from the wilderness - i:e., the desert part of Syria (1 Kings 19:15), the route from Assyria into Israel.
His spring shall become dry. Ephraim's resources shall be exhausted.
He shall spoil the treasure of all pleasant vessels - the Assyrian invader shall do so. Shalmaneser began the siege of Samaria in 723 BC Its close was in 721 BC, the first year of Sargon, who seems to have usurped the throne of Assyria while Shalmaneser was at the siege of Samaria. Hence, while 2 Kings 17:6 states, "the king of Assyria took Samaria," 2 Kings 18:10 says, "at the end of three years they took it." In Sargon's magnificent palace at Khorsabad inscriptions mention the number-27,280-of Israelites carried captive, by the founder of the palace, from Samaria and other places of Israel (George Vance Smith).