He said that if his wife gave birth to a third daughter he would divorce her, but he did not intend to divorce her
Question

                In a moment of anger, I was speaking to a friend of mine and he asked me what if I was given a third daughter? I said to him: If my wife gives birth to a third daughter, I will divorce her. But I did not mean what I said. Does this count as a divorce (talaaq)?
Praise be to Allah.
      Your saying “If my wife gives birth to a third daughter, I 
      will divorce her” comes under the heading of promising to divorce in the 
      future. If she gave birth to a daughter but you did not divorce her, then 
      nothing has happened. This is confirmed by the fact that you did not mean 
      what you said: you did not intend for a divorce to happen at that time and 
      you did not make it conditional upon her giving birth to a daughter. 

    But if you said, “If my wife gives birth to a third daughter 
    then she is divorced,” then divorce takes place if she gives birth to a 
    third girl. 

    You should beware of using the words of divorce (talaaq) in 
    ways other than that for which they were prescribed, namely ending a marital 
    relationship when the husband decides to do that for reasons which make it 
    permissible to divorce. 

    And Allah knows best.