Rumi is a 13th century Persian Sufi mystic, born in Balkh, in what is now Afghanistan. The general theme of his thoughts, like that of the other mystic and Sufi poets of the Persian literature, is essentially about the concept of Tawheed (unity) and union with his beloved (the primal root) from which/whom he has been cut and fallen aloof, and his longing and desire for reunity. - Text from Wikipedia
The following poem is one of my favorites:
Since You Are I, You Who Are Myself
Once a man came and knocked at the door of his friend.
“Who are you?” asked his friend. “It is I,” he replied.
The friend said, “Go away! This isn’t the time to enter!
There’s no place at a table like mine for the one
Who’s not been cooked in the fire of true gnosis?
Apart from the fire of absence and separation
What’ll cook the raw or free the uncooked from fraud?
The poor man went away and for a whole year of travel and absence
He was burnt utterly by the flames of separation.
His heart burned until it was consumed; he came again
To the door of his friend and knocked at the door
With a hundred signs of the utmost fear and reverence,
Terrified a wrong word should escape his lips.
From within, his friend called out, “Who’s at the door?”
He replied, “It is you who are at the door, O charmer of hearts!”
“Since you are I,” the friend said, “O you who are myself,
Enter; there’s no place in my house for two I’s.