He was assigned a grave with the wicked,
    and with the rich in his death,
though he had done no violence,
    nor was any deceit in his mouth.

The Hebrew of verse 9 is singular, and refers to ‘a rich man’. This verse was a puzzle until the events described in Matthew 27:57-60:

”As evening approached, there came a rich man from Arimathea, named Joseph, who had himself become a disciple of Jesus. 58 Going to Pilate, he asked for Jesus’ body, and Pilate ordered that it be given to him. 59 Joseph took the body, wrapped it in a clean linen cloth, 60 and placed it in his own new tomb that he had cut out of the rock. He rolled a big stone in front of the entrance to the tomb and went away. 61 Mary Magdalene and the other Mary were sitting there opposite the tomb.”

Barry Webb points out: ‘He was an innocent man who had been done to death like a criminal, and his burial was a mixture of honour and dishonour. If his career ended at that point it would be hard to tell what even God’s final verdict on him had been. Was his work finished to God’s satisfaction or not?’ ‘Isaiah’, p.212.

Well, we already know the answer.

If there is a glimmer in verse 9, it is going to develop into the full light of day