He said to his son: If you do not stop fighting, I shall divorce your mother
Question

                My husband is very hot-tempered and he uttered the word of divorce once, then after that on another occasion he did it twice. He is very bad tempered and on the third occasion he said to my son: If you do not stop fighting I shall say to your mother: You are divorced. What is the ruling on that?.
Praise be to Allah.
      If the 
      husband says to his son, “If you do not stop fighting I shall say to your 
      mother: You are divorced,” that does not count as a divorce as such, 
      because it is a threat to issue a divorce if the son persists in fighting. 
      Then if the husband wants to issue the divorce he may, and if he does not 
      want to, he may refrain. 

    Secondly: 

    If the divorce 
    is issued in a moment of anger, it is subject to further discussion. This 
    has been discussed in the answer to question number
    45174. 

    The husband 
    should fear Allah and avoid uttering the word of divorce in when angry or 
    otherwise, unless he actually intends to issue a divorce, after having 
    thought long and hard about the consequences. Divorce was not ordained to 
    let off steam in the case of anger; rather it was ordained to end a marriage 
    relationship in cases of necessity. 

    May Allah help us all to do that which He loves and pleases Him. 

    And Allah knows best.