Is the questioner sinful for letting her father break his fast in Ramadan due to his illness and change in behavior, and what should she do about his continued not fasting, and should she convince him to give up "al-naffah"?

Allah Almighty has commanded kindness and dutifulness towards parents, and to treat them with gentleness and good companionship. It was narrated from the Prophet, peace and blessings be upon him, that dutifulness to parents is among the deeds most beloved to Allah after prayer performed at its proper time.

One must be dutiful to parents and not retaliate against their mistreatment with similar mistreatment. A person is rewarded for enduring a father's mistreatment. If the father is able to fast, it is obligatory for him to do so. If fasting harms him, he is permitted to break his fast based on the advice of a knowledgeable doctor.

The father's advice can be disregarded if it is known that it will not be beneficial, or if harm will result from it, and there is no sin incurred in such a case. Giving advice is obligatory according to one's capacity, unless harm is feared.

"Naffa" (chewing tobacco) is forbidden, and its consumption is prohibited for both fasting and non-fasting individuals. Its consumption invalidates the fast. The justifications mentioned by the father are not to be considered, and the fatwa permitting the consumption of "naffa" to avoid cursing and insults is not clear.