Jalal al-Din Mohammad Rumi (1207-1273), was one of the greatest mystical poet of Iran. Here is a heart warming poem from his magnum opus Divan-e-Shams-e Tabrizi.

Passage

Thee I choose, of all the world, alone;
Wilt thou suffer me to sit in grief?
My heart is as a pen in thy hand,
Thou art the cause if I am glad or in melancholy.
Save what thou wills, what will have I?
Save what thou shows, what do I see?
Thou makes grow out of me now a thorn and now a rose;
Now I smell roses and now pull thorns.
If thou keeps me that, that I am;
If thou would have me this, I am this.
in the vessel where thou gives colour to the soul,
Who am I? What is my love and hate?
Thou wert first, and last thou shall be;
Makes my last better than my first.
When thou art hidden, I am of the infidels;
When thou art manifest, I am of the faithful.
I have nothing, except thou has bestowed it;
What dost thou seek from my bosom and sleeve?

Reynold Nicholson. Selected Poems from Divani Shamsi Tabriz. C.J. Clay & Sons, 1898.