Instead of the thorn shall come up the fir tree, and instead of the brier shall come up the myrtle tree: and it shall be to the L for a name, for an everlasting sign that shall not be cut off.

-Bible (Old Testament)
ORDIsaiah 55:13.

And lest I should be exalted above measure through the abundance of the revelations, there was given to me a thorn in the flesh, the messenger of Satan to buffet me.

-Bible (NewTestament)
Corinthians12:7.

The year's at the spring, And days at the morn; Morning's at seven; The hill-side's dew-pearled; The lark's on the wing; The snail's on the thorn; God's in His heavenö All's right with the world.

-Browning, Robert
Pippa Passes, pt.1.

And my fause Luver staw my rose, But, ah! he left the thorn wi'me.

-Burns, Robert
  'The Banks o' Doon' (2nd version), stanza 2.

Of all the trees that grow so fair, Old England to adorn, Greater are none beneath the Sun, Than Oak, and Ash, and Thorn.

-Kipling, (Joseph) Rudyard
  Puck of Pook's Hill,'Tree Song'.

England shall bide till Judgement Tide By Oak, and Ash, and Thorn.

-Kipling, (Joseph) Rudyard
  Puck of Pook's Hill,'Tree Song'.

Flowers of all hue, and without thorn the rose.

-Milton,John
  Paradise Lost (published1667), bk.4, l.256.

  A weary lot is thine, fair maid, A weary lot is thine! To pull the thorn thy brow to braid, And press the rue for wine!

-Scott, Sir Walter
  Rokeby, canto 3, stanza 28,'Song'.