Isaiah says that Yahweh of hosts will be the crown of glory and a beautiful diadem for those who are the remnant of his people. In other words, the chosen few will take on Yahweh’s spiritual leadership. Yahweh will be the spirit of justice for them. He will give them strength to hold back the enemy at the gate.
The righteous (δίκαιοι) will live forever (τὸν αἰῶνα ζῶσ). The Lord (Κυρίῳ) gives them this reward. The Most High God (῾Υψίστου) takes care of them. They will receive a glorious crown and a beautiful diadem from the Lord. His right hand (ἐκ χειρὸς Κυρίου) will cover him. His arm will provide a shield for them.