Analysis:
This quatrain by Saadi Shirazi presents a powerful dilemma faced by a lover. Let's break down each line:

Line 1: یا روی به کنج خلوت آور شب و روز

"Either turn your face to the corner of solitude night and day,"
The speaker suggests that the lover has two options: to retreat into solitude and hide their love, or to embrace it fully.

Line 2: یا آتش عشق بر کن و خانه بسوز

"Or kindle the fire of love and burn down the house."
This line is more dramatic, suggesting that if the lover chooses to love, they must be prepared for the consequences, even if it means destroying everything they hold dear.

Line 3: مستوری و عاشقی به هم ناید راست

"Secrecy and love do not agree,"
Here, the speaker states that love and secrecy are incompatible. True love, the quatrain implies, cannot be hidden.

Line 4: گر پرده نخواهی که درد، دیده بدوز

"If you don't want the curtain of pain to pierce your eyes."
This line suggests that hiding one's love will ultimately lead to pain. The "curtain of pain" symbolizes the emotional turmoil that comes from suppressing one's feelings.

Deeper Meaning:
This quatrain presents a stark choice: to love openly and risk pain, or to hide one's feelings and suffer in silence. The underlying message is that true love requires vulnerability and honesty. The lover is forced to confront the fact that love is often accompanied by pain, and that attempting to avoid this pain by hiding their feelings is futile.

Key themes:

The conflict between love and secrecy: The quatrain highlights the tension between the desire for love and the fear of pain and rejection.
The inevitability of pain in love: It suggests that love is often accompanied by suffering, and that trying to avoid this suffering is ultimately futile.
The importance of honesty and vulnerability: The quatrain emphasizes the need for openness and authenticity in love.

This quatrain is a powerful exploration of the complexities of love and the choices we make when faced with the possibility of heartbreak.