A son paying for his father's treatment and the mother giving him the amount from the father's money

Q: Your Eminence Grand Mufty of The Kingdom of Saudi Arabia (may Allah protect him); As-salamu `alaykum warahmatullah wabarakatuh (May Allah's Peace, Mercy, and Blessings be upon you). I hope that you will be patient enough to answer my question. Days after my father died in the last week of the month of Sha`ban, 1419 A.H. my mother invited me (Part No. 25; Page No. 263

A: all that your father left including money, real estate and whatsoever belong to the heirs. You should hope for reward from Allah for the money you assisted your father with during his illness and Hajj. This is a sign of dutifulness to your father. You should be grateful to Allah who helped you be dutiful to your father and treat him kindly. Do not take anything in return for that, especially that you assured your brothers that you are assisting your father seeking the pleasure of Allah. Indeed, Allah will reward you for that In sha’a-Allah (if Allah wills). Therefore, the money your mother saved for you belongs to the heirs.According to the number of the heirs in question, the estate is distributed as follows: your mother, who is the wife of the deceased, takes one eighth of the estate, and the residue is distributed among the children of the deceased where the male takes the share of two females.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.