Shaikh Abdul -Muhsin al-‘Abbad hafidhuhallah was asked:
Question: Do you raise your hands in this dua [i.e. When seeking forgiveness for the deceased after the burial]?
Answer: “The affair in that is spacious. We do not know of something that proves its affirmation nor denial. So a person can raise his hands [if he wills] or he does not raise his hands [if he wills]”.
[Sharh Sunan Abi Dawood no. 370]
However, Shaikh Fawzan said that one should raise his hands because raising the hands is a means for the supplication to be answered [https://www.alfawzan.af.org.sa/node/12963]
Faisal Ibn Abdul Qaadir Ibn Hassan