Some of the scholars are of the view that it is permissible to do any act of worship and to give the reward for it to the dead, whilst others are of the view that that is limited only to the acts of worship that are mentioned in the texts. 

Shaykh Saalih ibn Fawzaan (may Allaah preserve him) was asked: What are the things that will benefit the deceased if done by the living? Is there a difference between physical acts of worship and others? We hope that you can explain this matter to us and show us a principle to which we may refer whenever we are confused about such issues. Please advise us, may Allaah bless you. 

He replied: The living may benefit the deceased in the ways indicated by the evidence, such as saying du’aa’ for him, seeking forgiveness for him, giving charity on his behalf, performing Hajj and ‘Umrah on his behalf, paying off debts that he owes, and carrying out Islamically acceptable instructions left in his will. The evidence indicates that all of these are prescribed in Islam. 

Some of the scholars added to these all acts of worship that a Muslim does and gives the reward for it to another Muslim, living or dead. But the correct view is that it is limited only to those for which there is evidence, and that may be regarded as an exception to what Allaah says in the verse (interpretation of the meaning): 

“And that man can have nothing but what he does (good or bad)”

[al-Najm 53:39]

And Allaah knows best. 

Al-Muntaqa, 2/161

With regard to parents in particular, Islam regards the son as a source of his father’s earning good deeds. 

It was narrated that Abu Hurayrah (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “The good deeds that will reach a believer after his death are: knowledge which he learned and then spread; a righteous son whom he leaves behind; a copy of the Qur’aan that he leaves as a legacy; a mosque that he built; a house that he built for wayfarers; a canal that he dug; or charity that he gave during his lifetime when he was in good health. These deeds will reach him after his death.” Narrated by Ibn Maajah, 242; classed as saheeh Ibn Khuzaymah 4/121; classed as hasan by al-Tirmidhi and al-Albaani in Saheeh al-Targheeb 1/18. 

Al-Sindi said in his commentary on Sunan Ibn Maajah: 

A righteous child is regarded as part of a person’s deeds and good teaching, because the father is the reason for his existence, and he is the cause of his righteousness because he has taught him true guidance, just as Allaah said in the Qur’aan, describing the son of Nooh (peace be upon him), (interpretation of the meaning): “verily, his work is unrighteous” [Hood 11:46] (i.e., a person may be labeled according to his deeds). End quote. 

Shaykh al-Albaani (may Allaah have mercy on him) said: 

What a righteous son does of good deeds, his father will have a similar reward for them, without that detracting from his reward in the slightest, because his son is part of his efforts and his earning (of deeds). Allaah says (interpretation of the meaning): 

“And that man can have nothing but what he does (good or bad)”

[al-Najm 53:39]

And the Messenger of Allaah (peace and blessings of Allaah be upon him) said: “The best that a man consumes is what he earns, and his son is part of his earnings.” Narrated by the four authors of al-Sunan and classed as saheeh by Shaykh al-Albaani because of corroborating reports. End quote from Ahkaam al-Janaa’iz, p. 126, 217. 

Shaykh Saalih al-Fawzaan (may Allaah preserve him) was asked: 

What are the deeds that will benefit one’s parents, whether they are alive or dead? 

He replied: These deeds are: honouring them when they are alive, treating them kindly in word and deed, taking care of their needs for maintenance, accommodation and other things, feeling happy to be with them, speaking nicely to them and serving them, because Allaah says (interpretation of the meaning): 

“And your Lord has decreed that you worship none but Him. And that you be dutiful to your parents”

[al-Isra’ 17:23]

especially when they grow old.  

After they die, the ways of honouring them that remain are making du’aa’ for them, giving charity on their behalf, doing Hajj and ‘Umrah on their behalf, paying off debts that they owe, upholding the ties of kinship that one has through them, honouring their friends, and carrying out their last wishes that are in accordance with Islam. End quote.

Al-Muntaha, 2/162. 

Secondly: 

With regard to women observing i’tikaaf, i’tikaaf is mustahabb for men and women, but in the case of women it is subject to the condition that it be done with the permission of the woman’s family or husband, and that there should be no fitnah caused by her observing i’tikaaf.

  Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allaah have mercy on him) said:  

A woman may observe i’tikaaf so long as her doing so does not involve any fitnah. If it involves any fitnah, then she should not be allowed to do that, because if something forbidden results from something that is mustahabb, it must be prevented, just as if something forbidden results from something that is permissible, it must be prevented. If we assume that if she observes i’tikaaf in the mosque there will be fitnah, such as happens in al-Masjid al-Haraam, because in al-Masjid al-Haraam there is no place that is just for women, and if a woman observes i'tikaaf she will inevitably have to sleep, whether at night or during the day, and if she sleeps among men who are coming and going there will be fitnah.

 The evidence that i’tikaaf is prescribed for women is the fact that the wives of the Prophet (peace and blessings of Allaah be upon him) observed i’tikaaf during his lifetime and after his death. But if there is the fear of fitnah, then a woman should not be allowed to do it, because the Prophet (peace and blessings of Allaah be upon him) forbade things that were less that that. When he (peace and blessings of Allaah be upon him) wanted to observe i’tikaaf he went out one day and saw a tent for ‘Aa’ishah and a tent for others of his wives. He (peace and blessings of Allaah be upon him) said: “Is it righteousness that you seek?!” then he ordered that the tents be taken down, and he did not observe i’tikaaf that year, and he made it up in Shawwaal. This indicates that if a woman’s i’tikaaf will result in fitnah, it should not be allowed. End quote. 

Al-Sharh al-Mumti’, 6/510, 511 

Conclusion: A person should do a lot of righteous deeds on his own behalf, before his life comes to an end and his deeds are cut off. His parent will have a share of the reward for these deeds without that detracting from their children’s reward. I’tikaaf is a righteous deed, but in the case of a woman it must be done according to the guidelines and conditions as stated by Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him). 

And Allaah knows best.