It would be hard to find the equivalent, in terms of contrast, of the Roman ceremonies of Palm Sunday. It's easy to explain historically: Rome had long celebrated the Sunday before Easter as a commemoration of the passion of the Lord with all the pompous mourning of which she was capable. But then from the Franks came this other ceremony, quite joyful and even jubilant, of the procession of palms. And so we got this Mass of mourning preceded by a procession of joyful exuberance. Is it nonsense, or is there something else?
In reality it is one of the historical developments in the liturgy that happened gradually, and immensely enriched the Roman liturgy, like so many other of the Frankish elements that were adopted by Rome (and many of which were jettisoned from the modern Roman liturgy). It was certainly willed by Divine Providence. Why? Because the triumphal procession of the palms is actually an anticipation of the Resurrection, which would only come about through the Passion.
When Our Lord aroused in the minds and hearts of the Jews the enthusiasm of the first Palm Sunday, He knew perfectly well that, a few days later, the same people would be crying out for His Blood. He knew it, and that's exactly why He wanted this first Palm Sunday procession to take place.
What does it mean? It means that the Passion is in reality a triumph. It means that, contrary to appearances, the One who is victorious on Good Friday is the one who is condemned to death. It means that the crown of thorns is actually a crown of glory, and that the cross is the most splendid title of honour and nobility that the world has ever known.
What does it mean for us, and why is the procession of the palms so important that the Church mandates that we reenact it each year? Because it teaches us in the most eloquent manner that it is through the cross that we come to glory. It shows us that it is when we are weak that we are strong. It makes clear to the whole world that the blood of martyrdom is the palm of glory. And that is why, in the Book of Apocalypse, the elect stand in the glory of the Lamb with palms in their hands singing Alleluia!
So let us, during this Holy Week, turn our eyes with greater intensity to Calvary, certain that the more we take part in the sufferings of our dear Saviour, the more surely will we participate in the glory of His resurrection.
Don't forget the palms and the blood. They go together.