Why did Lowell choose a leper to confront Sir Launfal?

Words and Phrases for Discussion.

"We Sinais climb and know it not"
"Behold it is here--the Grail in my castle here is found"
"With our faint hearts the mountain strives"
"Then Heaven tries earth if it be in tune"
"For a god goes with it"
"Himself the Gate whereby men can Enter the temple of God in Man"
"She entered with him in disguise"
"He must be fenced with stronger mail"


YUSSOUF

JAMES RUSSELL LOWELL

A stranger came one night to Yussouf's tent,
Saying, "Behold one outcast and in dread,
Against whose life the bow of power is bent,
Who flies, and hath not where to lay his head;
I come to thee for shelter and for food,
To Yussouf, called through all our tribes 'The Good.'"

"This tent is mine," said Yussouf, "but no more
Than it is God's; come in, and be at peace;
Freely shalt thou partake of all my store
As I of His who buildeth over these
Our tents His glorious roof of night and day,
And at whose door none ever yet heard 'Nay.'"

So Yussouf entertained his guest that night,
And, waking him ere day, said: "Here is gold;
My swiftest horse is saddled for thy flight;
Depart before the prying day grow bold."
As one lamp lights another, nor grows less,
So nobleness enkindleth nobleness.

That inward light the stranger's face made grand,
Which shines from all self-conquest; kneeling low,
He bowed his forehead upon Yussouf's hand,