Answer
Wa `alaykum As-Salamu wa Rahmatullahi wa Barakatuh
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
A husband may wash to his dead wife even as a wife can bathe her dead husband.
Responding to your question, Sheikh Ahmad Kutty, a senior lecturer and an Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states:
A husband may give bath to his dead wife even as a wife can bathe her dead husband. That is according to the majority of scholars. There is a minority, however, who do not allow that. The evidence in the sources supports the majority view; so, it is perfectly fine to do so.
Imam Ahmad and Ibn Majah report on the authority of Aishah, the beloved wife of the Prophet, peace be upon him: “The Prophet once returned from Janazah in the Baqi’ while I was experiencing headache and I complained saying: My head hurts. He said, “No. It is my head that hurts more. If you were to die of your headache, I would bathe and shroud and pray over you.”
Imam Ash-Shafi`i, Ad-Daraqutni and al-Bayhaqi report on the authority of Asma bint Umays that Fatimah (the daughter of the Prophet left a will to the effect that Ali (her husband) should bathe her.”
Imam An-Nawawi states: A person may bathe his wife; it is the view of our school; it is also the view of the majority of scholars as Ibn al-Mundhir states citing many eminent scholars of the past.
As for a wife bathing her husband, it also has strong support in the sources:
Ibn al-Mundhir has cited the consensus of scholars that a woman is allowed to wash her husband.
We learn from the sources that it was Asma bint Umays who washed her husband Abu Bakr, the 1st Caliph; if it had been objectionable, the Companions – who were present – at the time.
In conclusion, a husband can bathe his deceased wife even as a wife can bathe her husband.
Almighty Allah knows best.
Source: Askthescholar.com