What is the author's message in "A Thousand Splendid Suns"?

The author's message is one of hope.  At the end of the story, Tariq and Laila are reunited with their daughter and she gets away from the cruel and violent Rasheed. 

"Laila and Tariq run away with both children and live in Pakistan. But after the United States invades Afghanistan, the family returns to Kabul. Their love for each other, as well as their love for their homeland, despite its cruelties and harshness and hardships, ends the novel on a high note, suggesting the possibility of a better future."

The author's message is technically referred to as the  theme, which is the overarching idea that the author presents.  Generally the theme is a message about life, or the "moral" of the story. 

 When thinking about the theme of this novel, think about what the main characters learned.  Mostly, the women of the story learned the benefits and consequences of love, and how that love can destruct or compliment a person. 

What is the message of A Thousand Splendid Suns?

A Thousand Splendid Suns delivers a message of hope and optimism. For example, despite all the hardships she suffers, including sacrificing her life to save Laila and Laila's children, Mariam's life has meaning and worth. She lives on through Laila's memories and through the orphanage. The patriarchy might demean and oppress women, but both Mariam and Laila are able to transcend that through their friendship, faith, and solidarity.

Mariam's sacrifice of her own life in killing Rasheed expresses in moving terms her belief in the possibility of a better life for Laila outside of a world of patriarchal oppression. She takes action for the good, paradoxically, when she crushes Rasheed's head with the shovel to save her friend. She also shows courage and integrity when she takes responsibility for what she has done in terms of taking a life—even if was to defend the life of her friend—and accepts her execution.

Laila expresses the novel's message of hope in religious terms at the end of the story, as she visits the bright, well-ordered orphanage. There she thinks, "Hovels shall turn to rose gardens, grieve not." She thinks as well, that even if floods should come, "Noah" will be with them. The arc of history, in other words, bends towards hope for a brighter future.

Laila also makes the decision not to continue to grieve Mariam's death:

Mariam is never very far ... Mariam is in Laila's own heart, where she shines with the bursting radiance of a thousand splendid suns.

The protagonists in this novel suffer greatly, but the novel's message is that the human spirit is strong.

What is the universal theme of A Thousand Splendid Suns?

It is very problematic to suggest that a work of literature has but one theme, as the very nature of literature is to open itself to a wide variety of different meanings that can be read into it through the reader and the reader's own understanding and context.

However, having said this, one of the major themes is the treatment of women in this novel and the various ways in which they are supressed, abused and mistreated. Afghanistan under the Taliban is shown to be a patriarchal world taken to its logical and terrifying extreme, with women forced to wear burkas and having no choice in whom they marry and no rights whatsoever. This is of course why Laila suffers so greatly because she was raised by her father to believe in herself and have a voice. The reality of her life with Rasheed is thus incredibly difficult for her. This is also why there was never any hope of justice for Mariam for her murder of Rasheed. Men were considered superior to women in any matter of law or justice.

Linked to this theme is the way that women are shown to live their lives in fear. The various examples of violence against women, both in the domestic sphere and in the wider sphere, reinforce the powerless position that women occupied and the way in which they could be abused at any moment with no hope of justice or salvation.