For thus saith the Lord God - The design of this verse is to give a reason for the destruction that should come upon them. That reason was, that God had indicated to them the path of truth and safety, but they chose not to follow it, and refused to put confidence in him.
In returning - In returning to God; that is, if you are converted to him.
And rest - That is, by calmly reposing on God for assistance, and not seeking the alliance of Egypt (see Exodus 14:13).
In quietness - In a collected, quiet state of mind.
In confidence - By putting simple trust in God.
Shall be your strength - You shall be safe; your enemies shall not be able to overcome and subdue you.
But ye would not - When Jerusalem was threatened by Sennacherib, Hezekiah did put this confidence in God, and reposed calmly and securely on his promises Isaiah 36:15, Isaiah 36:18, Isaiah 36:21; but it is not improbable that when the city was first threatened, and Hezekiah heard of the preparations made by the Assyrians, he had joined with the party in Jerusalem who proposed an alliance with Egypt, and that this was known to Sennacherib Isaiah 36:6. Probably, however, before the invasion had actually commenced he had seen the impropriety of this, either because the aid of Egypt could not be secured, or because Isaiah had warned him of this, and had been brought to put his trust entirely in Yahweh. Yet the offence had been “committed” of refusing to put implicit confidence in Yahweh, and of seeking the aid of Egypt, and for that the punishment is threatened in this chapter Isaiah 30:16-17.