I stand beneath the tree, whose branches shade
Thy western window, Chapel of St. John!
And hear its leaves repeat their benison
On him, whose hand thy stones memorial laid;
Then I remember one of whom was said
In the world's darkest hour, "Behold thy son!"
And see him living still, and wandering on
And waiting for the advent long delayed.
Not only tongues of the apostles teach
Lessons of love and light, but these expanding
And sheltering boughs with all their leaves implore,
And say in language clear as human speech,
"The peace of God, that passeth understanding,
Be and abide with you forevermore!"

Henry Wadsworth Longfellow

http://www.poemhunter.com/poem/st-john-s-cambridge/