Their father is senile and divorced their mother – did divorce really take place? And should they put him in a home for the elderly?
Question

                My father is bedridden and very sick; sometimes he does not know what he is saying, and at other times we find that he is very focused and can calculate money. He often insults religion and has weak eyesight and cannot hear at all. Often he urinates in the bed then throws his urine on the floor, then when we come and ask him, sometimes he denies it and sometimes he does it to annoy us and force us to wipe it up. One time my mother did wudoo’ then he called her, so she went to him, and he threw urine at her. She told him off and he said: “I am going to divorce you.” A little while later he said, “You are divorced.” What about this divorce? How should we deal with this father who is now in a very bad state and we cannot bear it. Can we put him in a home for the elderly?.
Praise be to Allah.
    It seems from what your father is doing that he has reached 
    the stage of senility, at which the obligations of sharee’ah are waived, so 
    he is not expected to pray or fast, and any vows, oaths or words of divorce 
    spoken by him are invalid. 

    If you can be patient and put up with the things he does, 
    then you should do that. If you cannot bear it, then there is nothing wrong 
    with you taking him to a home that takes care of the elderly, on condition 
    that you carry on honouring him and visiting him, and meeting his physical 
    and emotional needs as much as you can. 

    You should note that Allaah has enjoined honouring parents, 
    especially when they reach old age, because of their great need at that 
    time. Allaah has forbidden mistreating parents in word or deed, even by 
    saying “Uff” (a mild expression of displeasure). 

    Allaah says (interpretation of the meaning): 
“And your Lord has 
    decreed that you worship none but Him. And that you be dutiful to your 
    parents. If one of them or both of them attain old age in your life, say not 
    to them a word of disrespect, nor shout at them but address them in terms of 
    honour
And lower unto them the 
    wing of submission and humility through mercy, and say: ‘My Lord! Bestow on 
    them Your Mercy as they did bring me up when I was young.’”

    [al-Isra’ 17:23]

    Shaykh ‘Abd al-Rahmaan al-Sa’di said: 

    Then after mentioning His rights, Allaah mentions the rights 
    of parents and says, “And that you be dutiful to your parents” i.e., 
    you should treat them kindly in all ways, in word and deed, because they are 
    the reason why a person exists and because they love their child and treat 
    him kindly, which confirms that the child in turn is obliged to treat them 
    kindly.  

    “If one of them or both of them attain old age in your 
    life” means, if they reach the age at which they grow weak and need 
    kindness and good treatment, “say not to them a word of disrespect”: 
    the word “uff” is the least kind of offensive speech, and what is meant is 
    do not mistreat them in the slightest. 

    “Nor shout at them” means, do not rebuke them or speak 
    to them in a disrespectful manner. “But address them in terms of honour” 
    means, in a polite, gentle and kind manner, which will soften their hearts 
    and give them peace of mind. That varies according to circumstances, customs 
    and times. 

    “And lower unto them the wing of submission and humility 
    through mercy” means, be humble towards them and compassionate, seeking 
    reward thereby, not because you are afraid of them or hope for what they 
    have and other motives for which a person will not be rewarded. 

    “And say: ‘My Lord! Bestow on them Your Mercy” means: 
    pray for Allaah’s mercy for them during their lifetime and after they have 
    died, in return for their having brought you up when you were young. 

    From this it may be understood that the more time spent in 
    looking after their child, the greater their rights. Also, whoever takes 
    care of raising a person and teaching him properly about his religious and 
    worldly affairs instead of his parents has similar rights over the one whom 
    he raised. 

    Tafseer al-Sa’di, p. 407, 408 

    And Allaah knows best.