Five Matters in Which One is Dutiful to His Parents

Question :

How is one dutiful to his parents? Is it allowed to perform "Umrah on behalf of one of them, despite the fact that they already performed it?

Answer:

Being dutiful to your parents means helping them with A your wealth, your position, helping them physically, or being good to them in any other way, and this is obligatory. Being undutiful to them not fulfilling their rights and not being kind to them is from the major sins. And this can be, as mentioned previously, with the wealth, position, or physically etc.

After they die, you can be dutiful to them by supplicating for them, asking Allah to forgive them, executing their will, venerating their friends, and nurturing ties with relations that are only related to you through them. These are five ways to be dutiful to one's parents after they have died.

As for giving charity on their behalf, it is lawful, but we do not order a son to do so; rather, we say to him that if he gives charity on their behalf, it is lawful, but supplicating for them is better. This is because the Prophet ﷺ said:
"When someone dies, his deeds come to an end, except for three: A charity whose effect continues, knowledge (that he leaves behind) that is benefited from, and a righteous son who supplicates for him."

The Messenger of Allah ﷺ gave this supplication the status of a new deed. This proves that supplicating for one's parents after they die is better than giving charity on their behalf, better than performing 'Umrah for them, better than reading Qur'an for them, and better than praying on their behalf. This is because it is not possible for the Prophet ﷺ to leave mentioning what is superior while only mentioning what is inferior. He is required to mention what is superior and to mention what is allowed. He mentioned what was best in the last Hadith and in another Hadith of Sa'd bin 'Ubadah when a man sought permission from the Prophet ﷺ to give charity on behalf of his mother he permitted him, and similarly the case of the man who said, "O Messenger of Allah! My mother died unexpectedly and I think that if she had lived longer she would have given some charity. May I give charity on her behalf? He replied yes.

I am only stressing the importance of the brother supplicating for his parents over giving charity on their behalf and the like because that is what the Prophet ﷺ guided us to. This being so, we do not condemn someone for giving charity, performing 'Umrah, praying, or reading Qur'an, intending these deeds on behalf of his parents or one of them. In case that the parent did not perform the obligatory Hajj or 'Umrah, it is said that performing an obligatory deed on their behalf is better than supplicating for them. And Allah knows best.

Source:
Ibn 'Uthaimin
Fatawa Islamiyah, Vol. 7 Pages 326-327