Isaiah 7:9

“And the head of Ephraim [is] Samaria, &c.]. Samaria was the metropolis or chief city of Ephraim, or the ten tribes of Israel: and the head of Samaria [is] Remaliah’s son; Pekah, son of Remaliah, was king of Samaria, as of all Israel. The sense is, that, until the sixty five years were ended, there should be no enlargement of the kingdom of Israel; Judah should not be added to it; Samaria should continue, and not Jerusalem be the metropolis of it; and Pekah, during his life, should be king of Israel, but not of Judah. If ye will not believe; the Targum adds, “the words of the prophet;” surely ye shall not be established, or remainf128; that is, in their own land, but should be carried…”

“believe, . . . be established--There is a paronomasia, or play on the words, in the Hebrew: "if ye will not confide, ye shall not abide." Ahaz brought distress on himself by distrust in the Lord, and trust in Assyria.”

“And the head of Ephraim - The capital city of Ephraim, or of Israel. Is Samaria - This was long the capital of the kingdom of Israel. For a description of this city, see the notes at Isaiah 28:1. The meaning of the prophet is, that Samaria should continue to be the head of Ephraim; that is, Jerusalem should not be made its capital. If ye will not believe, surely ye shall not be established - There is considerable variety in the interpretation of these words, though the general sense is evident. The Chaldee renders them, ‘If ye will not believe the words of the prophet, ye shall not remain.’ It is probable that Ahaz, who was greatly alarmed, and who trembled at the formidable power of Syria…”

“Samaria - Samaria shall continue to be the chief city if the kingdom of Israel, and Pekah shall not conquer Jerusalem. If - If you do not believe this, but seek to the Assyrians for succour, ye shall be consumed thereby. Isaiah 7:12”

“7:9 The last sentence is a play on two Hebrew words: If you do not have faith (ta’aminu), you will not stand firm (te’amenu). Firm trust in the Lord is utterly essential, especially for a leader of God’s people (see also 2 Chr 20:20), and it must be firmly acted upon in order to demonstrate that it exists. Ahaz and his contemporaries trusted their enemy (Assyria) rather than God. By contrast, Hezekiah later demonstrated his faith in the Lord in a similar context (see Isa 36–38).”

“the head: Kg1 16:24-29; Kg2 15:27 If ye: etc. or, ye not believe, it is because ye are not stable, Ch2 20:20; Act 27:11, Act 27:25; Rom 11:20; Heb 11:6; Jo1 5:10 Isaiah 7:10”