A:
Having good manners is part of Iman (faith) and good treatment is part of Islam; and every Muslim is required by Shari`ah (Islamic law) to observe these etiquettes. Allah (Glorified be He) dislikes insolence and bad manners and traits. Accordingly, the father should refrain from insulting his children and calling them names, because this involves sin and transgression and may turn the children into ill-mannered ones. You should advise him and his children should avoid provoking him or arguing with him, but at the same time they should be well behaved with him and ask Allah to guide him.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.