Yet I will distress Ariel - The reference here is doubtless to the siege which God says Isaiah 29:3 he would bring upon the guilty and formal city.
And there shall be heaviness and sorrow - This was true of the city in the siege of Sennacherib, to which this probably refers. Though the city was delivered in a sudden and remarkable manner (see the note at Isaiah 29:7-8), yet it was also true that it was reduced to great distress (see Isaiah 36; Isaiah 37)
And it shall be unto me as Ariel - This phrase shows that in Isaiah 29:1 Jerusalem is called ‘Ariel,’ because it contained the great altar, and was the place of sacrifice. The word “Ariel” here is to be understood in the sense “of the hearth of the great altar;” and the meaning is, ‘I will indeed make Jerusalem like the great altar; I will make it the burning place of wrath where my enemies shall be consumed as if they were on the altar of burnt sacrifice.’ Thus in Isaiah 30:9, it is said of Yahweh that his ‘fire is in Zion, and his furnace in Jerusalem.’ This is a strong expression, denoting the calamity that was approaching; and though the main reference in this whole passage is to the distress that would come upon them in the invasion of Sennacherib, yet there is no impropriety in supposing that there was presented to the mind of the prophet in vision the image of the total ruin that would come yet upon the city by the Chaldeans - when the temple, the palaces, and the dwellings of the magnificent city of David would be in flames, and like a vast blazing altar consuming that which was laid upon it.