The adversaries of Rezin against him "The princes of Retsin against him" - For צרי tsarey, enemies, Houbigant, by conjecture, reads שרי sarey, princes; which is confirmed by thirty of Kennicott's and De Rossi's MSS., (two ancient), one of my own, ancient; and nine more have צ tsaddi, upon a rasure, and therefore had probably at first שרי sarey . The princes of Retsin, the late ally of Israel, that is, the Syrians, expressly named in the next verse, shall now be excited against Israel.
The Septuagint in this place give us another variation; for רצין Retsin, they read ציון הר har tsiyon, ορος Σιων, Mount Sion, of which this may be the sense; but Jehovah shall set up the adversaries of Mount Sion against him, (i.e., against Israel), and will strengthen his enemies together; the Syrians, the Philistines, who are called the adversaries of Mount Sion. See Simonis Lex. in voce סכך sachach .
Therefore - This verse indicates the punishment that would come upon them for their pride.
The Lord shall set up - Hebrew, ‹Shall exalt.‘ That is, they shall overcome and subdue him.
The adversaries of Rezin - King of Syria, Isaiah 7:1. It should be observed here, that twenty-one manuscripts, instead of adversaries, read princes of Rezin. The sense seems to require this; as in the following verse, it is said that the Syrians will be excited against them.
Against him - Against Ephraim.
And join his enemies together - Hebrew, ‹Mingle them together.‘ They shall be excited into wild and agitated commotion, and shall pour down together on the land and devour it. In what way this would be done is specified in Isaiah 9:12.