Analysis:

This quatrain by Saadi Shirazi is a beautiful exploration of love, longing, and the subjective nature of beauty. Let's break down its meaning:

The Beloved's Beauty: The speaker is describing the incomparable beauty of their beloved, emphasizing their grace and a smile that is both subtle and captivating.
The Limitations of Sight: The speaker acknowledges that the beauty of the beloved is so profound that it cannot be fully captured or understood by mere sight.
The Invitation to the Eye: The speaker invites the listener to come into their eye, suggesting that the true beauty of the beloved can only be perceived through the lens of love.
The Subjectivity of Beauty: This quatrain emphasizes that beauty is not merely an objective quality but is subjective and deeply personal.

Themes:

Love and Beauty: The central theme is the speaker's deep love and admiration for their beloved.
Subjectivity of Beauty: The quatrain suggests that beauty is not merely physical but is also a matter of perception and emotion.
The Limits of Perception: The speaker acknowledges that the beauty of the beloved is beyond human comprehension.
Invitation to Share: The speaker invites the listener to share in their experience of love.

Deeper Meaning:

This quatrain is a celebration of the power of love to transform our perception of the world. The speaker suggests that true beauty cannot be seen with the physical eye but must be experienced through the heart. By inviting the listener to come into their eye, the speaker is sharing a deeply personal and intimate experience.

This quatrain is a beautiful expression of the subjective nature of beauty and the transformative power of love.