‘Now when morning was come, all the chief priests and the elders of the people took counsel against Jesus to put him to death.'
‘Now when morning was come.' Compare ‘when evening was come' in Matthew 26:20. The evening had brought the depiction of His death in the Lord's Supper, followed by His anguish and arrest, the morning will now bring His sentence and execution.
‘All the Chief Priests and Elders of the people.' Compare Matthew 26:3 where they had previously taken counsel how to kill Him. Now they were on the point of achieving their aim. Mark includes ‘the Scribes', but Matthew recognises that all Jews will know that there are Scribes among the priests and the elders of the people and therefore omits them. He is basically using this expression to indicate the whole Jewish leadership, the Sanhedrin. All will be involved in seeking Jesus' crucifixion.
‘Took counsel against Jesus', or more strictly ‘came to a decision about Jesus'. This was the official meeting of the Sanhedrin meeting by daylight (compare Mark 15:1; Luke 22:66), which followed the unofficial hearing during the night. Now the remainder of the counsel had to be convinced of Jesus' guilt. But it would not be too difficult to convince most of them, given what Jesus had said. It must be seen as very possible that some members were not present (for example Joseph of Arimathea), probably because they had been ‘accidentally' overlooked, or ‘could not be found'. Alternatively the vote which would presumably have taken place may not have been unanimous, but it is questionable if that would have accorded with their wishes.