ישעיהו ז:ב פירוש: רש״י ואבן עזרא

And it was told to the House of David Since he was wicked, Scripture did not mention his name.

Ephraim. The kingdom of the ten tribes is called Ephraim, because their first king Jeroboam was of that tribe (1 Kings 2:26).

Aram has allied itself with Ephraim lit. has rested upon Ephraim. The king of Aram has joined the king of Israel to attack you. נָחָה is the feminine gender, since the kingdom (מַלְכוּת) joined. Posad in O. F., lay, comp. (Exodus 10:14) “And it rested (וַיַָּנַח) in all the boundary of Egypt.”