He can pray Salāt on their behalf...

He can pray Salāt on their behalf, and give charity on their behalf, and perform Hajj on their behalf, and Fast on their behalf. Thus, that which he does for them both would happen to for him, the like of that, and Allah -azwj Mighty and Majestic would Increase him, due to his righteousness, and his kinship, a lot of good’.

Muhammad Bin Yahya, from Ahmad Bin Muhammad Bin Isa, from Moammar Bin Khalid who said, ‘I said to Abu Al-Hassan Al-Reza -asws , ‘Should I supplicate for my parents when they do not recognise the truth (Al-Wilayah)?’ He -asws said: ‘Supplicate for them both and give charity on their behalf; and if they were alive not recognising the truth (Al-Wilayah), so circle around them (introduce to them the Al-Wilyah), for Rasool-Allah -saww said: ‘Allah -azwj Sent me -saww with the Mercy, not with the ingratitude’.

Ali Bin Ibrahim, from his father, and Muhammad Bin Yahya, from Ahmad Bin Muhammad, altogether from Ibn Mahboub, from Malik Bin Atiyya, from Anbasa Bin Mus’ab, (It has been narrated) from Abu Ja’far -asws having said: ‘Three (matters), Allah -azwj Mighty and Majestic did not Give an allowance regarding these – Paying back the entrustment to the righteous and the immoral, and the loyalty with the pact to the righteous and the immoral, and being righteous with the parents, whether they were righteous or immoral’.