This entry of the humble Christ into the city was foretold and prophesied by the prophet, Zechariah:
Shout, Daughter of Jerusalem!
See, your king comes to you,
righteous and having salvation,
gentle and riding on a donkey, on a colt, the foal of a donkey.
I will take away the chariots from Ephraim
and the war-horses from Jerusalem,
and the battle bow will be broken.
He will proclaim peace to the nations.
His rule will extend from sea to sea
and from the River to the ends of the earth".
This service is a particularly fine one, albeit lengthy.
The palms are blessed with many hymns, chants and prayers, and the people receive them, the choir singing Pueri Hebraeorum, portantes ramos olivarum (the children of Israel carrying olive branches), and there is a short-form mass at the altar. After this comes the Procession out of the Church, singing Gloria, laus et honor, tibi sit, Rex Christe Redemptor, and then back to the front door thereof.
At the door, 2 cantors enter and the doors are shut. They continue to sing and then the Subdeacon, outside, knocks on the door with the end of the processional cross. The doors open, to signify the entrance of Christ into Jerusalem and our entry into Heaven, and the procession moves back into the church, singing an ancient chant, Ingrediente Domino.
Then the main mass begins with many haunting and beautiful chants being sung, and then the Passion according to St Matthew in long form is sung, starting at the anointing of the feet of Jesus by St Mary Magdalene in the house of Simon the Leper.
This is a fitting way to recall the beginning of the Passion when our Lord was welcomed as a king and prophet into the holy city of Jerusalem by His people who, only days later, were to betray Him unto their Roman enemies to torture and death.
Soon many of those same Romans were to be converted whilst many of God's chosen rejected the very Messias whom they had been awaiting for so long.
In former times, the celebrating priest would, for the procession, sit upon a donkey to which is attached its colt, as our Lord Himself so sat on the original Palm Sunday.
It is a remarkable fact that every donkey, of the sort upon which our Lord rode, has, by nature, marked upon its back, a black cross to signify the fact that, one day, the Creator of heaven and earth would sit upon the back of this same animal for His entry into the Holy City of Jerusalem, but one week before he would be led, in that came city, to death upon the Cross.
In former times, too, the Roman Emperor would lead the Patriarch on a donkey up to the church door as part of the ceremonies and as a gesture of humility on his part. Sadly, the tradition later died out.
This tradition was continued by the Russian Tsars, also, until the custom was suppressed by the modernising, "enlightened" and very brutal dictator, Tsar Peter I.
It is a fitting imitation of the humility of Christ for the supreme spiritual ruler to ride upon a donkey on this day, led by the supreme temporal ruler.
When fishes flew and forests walked
And figs grew upon thorn,
Some moment when the moon was blood
Then surely I was born.
With monstrous head and sickening cry
And ears like errant wings,
The devil's walking parody
On all four-footed things.
The tattered outlaw of the earth,
Of ancient crooked will;
Starve, scourge, deride me: I am dumb,
I keep my secret still.
Fools! For I also had my hour;
One far fierce hour and sweet:
There was a shout about my ears,
And palms before my feet.
Hosanna to the son of David!