Peter Pett's Commentary on the Bible
Isaiah 28:5,6
Flash Forward - The Coming Day of Deliverance (Isaiah 28:5).
In the future Yahweh will have a proper crown available for those who serve Him.
Analysis.
a In that day will Yahweh of hosts be for a crown of glory (Isaiah 28:5 a).
b And for a diadem of beauty, to the residue of His people (Isaiah 28:5 b).
b And for a spirit of judgment to him who sits in judgment (Isaiah 28:6 a).
a And for strength to those who turn back the battle at the gate (Isaiah 28:6 b).
In ‘a' Yahweh will be ‘for a crown of glory', and in the parallel will be ‘for strength' for those who defend His city. In ‘b' He will be a diadem of beauty, and in the parallel a spirit of judgment.
‘In that day will Yahweh of hosts be for a crown of glory,
And for a diadem of beauty, to the residue of His people,
And for a spirit of judgment to him who sits in judgment,
And for strength to those who turn back the battle at the gate.'
Suddenly in true Isaianic fashion we have a flash forward to the coming day when God will deliver His people. However dark the horizon Isaiah wishes to stress that beyond it is always Yahweh's deliverance for the remnant. The false crown of Samaria has brought to mind the true crown which His true people will receive, and the comparison is made accordingly. This therefore looks back to Isaiah 28:1. However the ‘spirit of judgment' looks forward to the following verses.
‘In that day', that is, whenever Yahweh steps in to deliver. The same pictures are used as in Isaiah 28:1 but this time they indicate something that is real and precious and lasting. One day Yahweh will be for a true crown of glory (not a crown of misplaced pride) and a genuine diadem of beauty (not a wilting diadem of flowers) to the residue of His people, one that they can truly wear with ‘pride'. Judgment may be coming but it will produce a residue, (but only a residue), on behalf of whom God can act. Gone will be the false pride and the wilting flowers of the past, replaced by this genuine glorious crown and beauteous diadem.
Then ‘the one who sits in judgment' will be filled with a spirit of judgment so that his judgments are in accordance with the divine will. This is in deep contrast to the present when His people can only learn little by little. Associated as this one is with the crown and the diadem, and spoken of in the singular, Isaiah may well have in mind here the coming Prince, the son of David (Isaiah 7:14; Isaiah 9:6; Isaiah 11:1). For He is the One who is coming to rule and will be given the spirit of wisdom in judgment (Isaiah 11:1).
Furthermore, those who guard the ‘weak point', the gate, of the strong city (Isaiah 26:1) will have the strength of Yahweh and be able to turn back any attack. It will no longer be a weak point. So in that day both prince and people will be strong with Yahweh's strength. Many, however, see it as referring to taking the battle to the gates of their enemies. Either way the point is that He will give certain victory.