Giving fidiyah for the prayers missed for a deceased parent. 1) Is this allowed?

Mufti Saab, Assalamu-alikum, My dear father passed away a couple of months back and alhamdulillah he was a very religious and pious man and was also involved in the work of Dawa'a. During his last days (7 or 8 days), sometimes he would miss the prayers as he would be asleep and unclean. Whenever awake, I would do tayammum for him, and he would pray lying on bed with signs, and at times while praying he would have dosed off. Someone asked me to give the fidiyah for all the prayers he missed. 1) Is this allowed? 2) Is there any hadith that supports fidiyah of this type ( I am requesting this reference to hadith as I can explain to others the need for giving fidiyah )