Buying cigarettes for the father and obeying him in sin

Question:
His other question says: My father is afflicted with smoking, may Allah protect us and you from that. He asks me to buy him cigarettes, and I refuse because I fear that I would be obeying him in disobedience to Allah the Mighty and Majestic. Is there a sin on me for that? Please give us a ruling, may Allah reward you with good.

Answer:
You should help your father in what Allah has forbidden. You tell him, "It is not permissible for me, O my father, it is not permissible. May Allah guide you. Fear Allah and give up smoking. Advise him with kind words and a good manner. Say, 'O my father, may Allah reward you with good. This harms you in your religion and your worldly life. Fear Allah. It is not permissible for me to obey you in this, because the Messenger (peace and blessings be upon him) said: The Messenger (peace and blessings be upon him) said: And he said: Smoking is forbidden and a sin. It is not permissible to obey you in it, just as it is not permissible to bring him wine or a woman for zina (unlawful sexual intercourse). One does not obey in sins, ever. Not in zina, not in wine, not in smoking, not in riba (usury or interest), nor in any other of these sins. Allah, Glorified and Exalted is He, said to His Prophet, 'And they do not disobey you in what is right.' How much more so in what is not right?"
His father. There is no obedience to a created being in disobedience to the Creator. But you address your father with kind words and a good manner. You say to him a gentle word. Allah said regarding the disbelieving parents, the disbelieving parents: So it is obligatory to address him with the best manner, and to advise him, but do not obey him in buying what is forbidden. Yes, yes.