Apparently Jesus had been flogged earlier, as part of his interrogation. Immediately after sentence of crucifixion was passed, Jesus was flogged again (v.26).
This was standard procedure; it was customary to flog prisoners before taking them out to be crucified. But what takes place in verses 27 to 31 is not standard procedure. It is more like barracks-room humour.
The governor’s soldiers gather around, strip Jesus of his clothes, and drape some sort of scarlet robe on him, pretending he is a royal figure. Then they wind together some strands of vine thorns, the spikes of which are 15-20 cm long. They crunch this down on his head to make a cruel crown of thorns. They put a staff into his hand and pretend it is a sceptre. Alternately bowing before Jesus in mock reverence and hitting him in brutal cruelty, they cry, ‘Hail, king of the Jews!’—and complete the acclamation by spitting in his face and hitting him again and again with the mock sceptre. Raucous, mocking laughter keeps the room alive until the soldiers tire of their sport. They have finished laughing at him as the king of the Jews. Now they put his own clothes back on him and lead him away to be crucified.
