This text comes from A First Series of Hymns and Songs, a historical songbook transcribed on Wikisource and reproduced from the pinned revision linked below.
Come, children, all whose joy it is
To serve at Holy Mass,
And hear what once in days of faith
In England came to pass.
It chanc'd a priest was journeying
Through wildering ways of wood;
And there, where few came passing by,
A lonely chapel stood.
He stay'd his feet, that pilgrim priest,
His morning Mass to say,
And put the sacred vestments on
That near the altar lay.
But who shall serve the Holy Mass,
For all is silent there!
He kneels him down, and patient waits
The peasant's hour of prayer.
When lo! a child of wondrous grace
Before the altar steals,
And down beside that lowly priest
In Infant beauty kneels.
He serves the Mass; his voice is sweet,
Like distant music low;
With downcast eye, and ready hand,
And footfall hush'd and slow.
"Et Verbum caro factum est,"
He lingers till he hears;
Then turning to the Virgin's shrine,
In glory disappears.
So round the altar, children dear,
Press gladly in God's name,
For once to serve at Holy Mass
The infant Jesus came.