Analysis:
This quatrain by Saadi Shirazi is a playful and somewhat suggestive piece. Let's break down each line:

Line 1: این ریش تو سخت زود برمی‌آید

"This beard of yours grows so quickly,"
The speaker is directly addressing someone and commenting on the rapid growth of their beard.

Line 2: گرچه نه مراد بود برمی‌آید

"Though it brings no desire,"
Here, the speaker implies that the beard, while growing quickly, is not serving any particular purpose or fulfilling any desire. This could be a subtle criticism of vanity or perhaps a hint at a deeper meaning.

Line 3: بر آتش رخسار تو دلهای کباب

"On the fire of your cheek, hearts burn,"
This line shifts the focus to the effect of the person's appearance, specifically their cheeks. The image of a "fire" on the cheek suggests a passionate or intense gaze that can ignite love or desire in others.

Line 4: از بس که بسوخت دود برمی‌آید

"And from so much burning, smoke arises,"
The final line continues the metaphor of fire, suggesting that the intensity of the person's gaze has caused such intense emotions in others that it has produced "smoke," symbolizing passion or perhaps even confusion.

Deeper Meaning:

This quatrain can be interpreted in several ways:

A playful tease: On a simple level, this could be a playful tease about someone's appearance or a lighthearted comment on the power of attraction.
A commentary on vanity: The reference to the beard growing quickly without serving a purpose might be a subtle criticism of vanity or superficial concerns.
A metaphor for passion: The image of a "fire" on the cheek and the resulting "smoke" suggests a deep passion or intense emotion.

This quatrain is a short, evocative piece that invites multiple interpretations. It plays with imagery and language to create a sense of mystery and intrigue.