Father may discipline but not abuse his son
6-10-2015 | IslamWeb
Question:
Asallam u Alaikum,With regards to previous question number 2548271 If parent said to child in anger 'you will be questioned by Allah about how you were with your parents, I will not' The parent was not trying to say that they will not be questioned at all about how they behaved with their children but that the son/daughter will have more responsibility to their parents so will be questioned more. They actually meant that if you are rude to me you will be questioned but if I am rude to you I won't . The statement was about talking back to parents or being rude to them.The parent later thought about this statement and repented. Was this Kufr?(Allah Forbid).
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad 
is His slave and Messenger.
The father is no doubt wrong for saying this because it is an assertion of a matter of the Unseen that no one knows except Allaah. Allaah says (what means): {And do not pursue that of which you have no knowledge. Indeed, the hearing, the sight and the heart - about all those [one] will be questioned.} [Quran 17:36]
If the father intended that Allaah will not hold him accountable for speaking harshly to his son, then this is not absolutely correct. But the father does have the right to discipline his son even if the latter is old in age. It was narrated that ‘Abdullaah ibn ‘Umar 
said that he heard the Prophet say: “"Do not prevent your women from going to the mosque if they seek your permission to go there." Bilaal ibn ‘Abdullaah (ibn ‘Umar) said: "By Allaah, we will prevent them." So, ‘Abdullaah turned to him and insulted him profusely in a way that I (the narrator) had never before heard from him. He said to him, "I tell you what the Prophet said and you say, 'By Allaah, we will prevent them.'"” [Muslim]
Al-Haafith Ibn Hajar said: “What can be concluded from ‘Abdullaah vehemently denouncing his son is that it is permissible to discipline someone who objects to the Sunnah with his own opinion, or objects to a scholar with his whims, and that it is permissible for a man to discipline his son even if the latter is old in age if he says something that he should not say, and that it is permissible to discipline by shunning the person.” [Fat-h Al-Baari]
It should be mentioned that parents have great rights with respect to their children and children are obliged to be kind and dutiful to their parents and it is forbidden to sever ties with them even if they mistreat their children, as the obligation of being kind and dutiful to them is not forfeited by this. Please refer to Fatwa 87019 and 87856.
Finally, we would like to emphasize that the matter of unbelief is not trivial. A Muslim is not declared an unbeliever even if he says or does something that is considered unbelief unless the conditions for that are met and its impediments are absent. Please refer to Fataawa 8106 and 87963 about the conditions for declaring someone an unbeliever.
Allaah Knows best.