...and one can also say:
أَعْظَمَ اللّٰهُ أَجْرَكَ، وَأَحْسَنَ عَزَاءَكَ، وَغَفَرَ لِمَيِّتِكَ
May Allah magnify your reward, and make perfect your bereavement, and forgive your departed.
A'dhamallaahu 'ajraka, wa 'ahsana 'azaa'aka wa ghafara limayyitika.