Departing the body upon burial becomes the purview of the mourners and the deceased, both. We say: Go in peace, in contrast to the good wishes for the living: Go to peace - there's more to go and do, for the living. Plus, the importance of the language we use at this time, as based on biblical verses. Also, a closing note on occupying yourself with prayer and Torah study, and an ever increasing movement forward and upward. Plus, the notion that death isn't the end of our doing good, then in the World to Come.