Analysis:

This quatrain by Saadi Shirazi expresses a deep and passionate love for a friend. The speaker is essentially saying that if they were to love anyone, it would be this particular friend. Let's break down each line:

Line 1: گر دل به کسی دهند باری به تو دوست

"If I were to give my heart to anyone, surely it would be to you, my friend,"
The speaker is conditionally offering their heart, but only to this particular friend. This suggests a strong emotional connection.

Line 2: کت خوی خوش و بوی خوش و روی نکوست

"For you have a pleasant disposition, a sweet scent, and a beautiful face."
Here, the speaker lists the qualities that make this friend so desirable. The reference to a "sweet scent" is a poetic device common in Persian poetry to describe beauty and desirability.

Line 3: از هر که وجود صبر بتوانم کرد

"I can endure the absence of anyone,"
The speaker claims that they can tolerate the absence of anyone else. This suggests that they have a strong ability to endure hardship or separation.

Line 4: الا ز وجودت که وجودم همه اوست

"Except for you, whose existence is my whole existence."
This final line is the most powerful. The speaker states that they cannot endure the absence of this friend because the friend's existence is intertwined with their own. This suggests a deep level of emotional dependence.

Themes explored in the quatrain:

Deep friendship: The quatrain explores the depth and intensity of a friendship.
Beauty and desirability: The physical attributes of the friend are described in poetic terms, highlighting their attractiveness.
Emotional dependence: The speaker reveals a deep emotional dependence on the friend, suggesting that their existence is incomplete without the friend.

This quatrain is a beautiful expression of deep friendship and affection. The speaker's willingness to give their heart to this friend, coupled with the description of their physical and emotional qualities, creates a powerful and moving image of love and devotion.