Losing a loved one is a painful experience. One of the best things we can give to our loved one who has passed away and is going ahead to the next life is sincere dua.
This is a beautiful dua mentioned in Sahih Muslim that the Prophet Muhammad (saw) recited at a funeral:
“O Allah, forgive and have mercy upon him, excuse him and pardon him, and make honourable his reception. Expand his entry, and cleanse him with water, snow, and ice, and purify him of sin as a white robe is purified of filth. Exchange his home for a better home, and his family for a better family, and his spouse for a better spouse. Admit him into the Garden, protect him from the punishment of the grave and the torment of the Fire.” (Muslim)