Analysis:

This quatrain by Saadi Shirazi uses the metaphor of a candle to convey a deeper meaning about human behavior and the nature of suffering.

Line 1: شمع ارچه به گریه جانگدازی می‌کرد

"Though the candle wept, causing the heart to ache,"
The candle, a symbol of life and hope, is depicted as weeping. This suggests that even the most enduring of things can suffer and feel pain.

Line 2: گریه زده خندهٔ مجازی می‌کرد

"Amidst its tears, it forced a false smile."
Despite its pain, the candle tries to maintain a facade of happiness. This is a commentary on human behavior, where people often mask their suffering with a smile.

Line 3: آن شوخ سرش را ببریدند و هنوز

"They cut off the head of that playful one, and still"
The metaphor shifts to a more literal image of a playful person whose head has been cut off. This suggests a violent or sudden end to something.

Line 4: استاده بد و زبان‌درازی می‌کرد

"It stood and wagged its tongue."
Even after its head has been severed, the body continues to move. This could be interpreted as a symbol of defiance or a refusal to accept one's fate.

Themes explored in the quatrain:

Suffering and resilience: The candle's continued burning despite its pain and the decapitated body's continued movement suggest a resilience in the face of suffering.
Falsehood and deception: The candle's forced smile represents the human tendency to mask our true feelings.
The nature of life and death: The image of the decapitated body continuing to move raises questions about the nature of life and what it means to be truly dead.

This quatrain is a complex and evocative meditation on the human condition. Through the metaphor of the candle, Saadi explores themes of suffering, resilience, and the nature of life and death.