All that is gold does not glitter,
Not all those who wander are lost;
The old that is strong does not wither,
Deep roots are not reached by the frost.
This line, and its reversal, is a foreshadowing of the perception of Aragorn. When we first meet him in Bree, he creeps out Frodo and is described in a somewhat prejudiced way by the innkeeper. His role then expands, as he leads the chase for Merry and Pippin, has the sword reforged, and so on. By the end of the books, he is king in Gondor. 
 The line is also an inversion of the famous remark by the Prince of Morocco in Shakespeare’s  The Merchant of Venice  (Act 2, Scene 7): 
 All that glisters [i.e. glitters] is not gold. 
 The American pop rock band  Smash Mouth  played their own variation on this line, arguing in their 1999 hit “ All Star ” that “All that glitters is gold.” 
 
 If you got Shakespeare, Tolkien, and Smash Mouth together in a room to hash this out, there would be no consensus, but you’d fulfill the lifelong dream of a few million nerds born in 1983. Not to mention that Led Zeppelin referenced the line as well: 
 
 On a more tragic note, Thomas Gray incorporates this phrase into his  “Ode on the Death of a Favorite Cat, Drowned in a Tub of Gold Fishes.”