For instead of a diadem, they put upon Him a crown of thorns, and a purple robe to represent the purple robe which kings wear. Matthew says, a scarlet robe, (Mat. 27:28) but scarleta and purple are different names for the same colour. And though the soldiers did this in mockery, yet to us their acts have a meaning. For by the crown of thorns is signified the taking of our sins upon Him, the thorns which the earth of our body brings forth. And the purple robe signifies the flesh crucified. For our Lord is robed in purple, wherever He is glorified by the triumphs of holy martyrs.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).