Several things contribute to this view. The 10 meditations on the corpse are included in the Buddhist doctrine to lead towards dispassion. Dispassion is encouraged to lead towards salvation - salvation from death and decay.
The Christian doctrine of raising the dead implies that the soul lies dormant, but not necessarily unconscious, in the corpse. Thus, the wisdom of the ages has long held to a belief that there is some remnant of our being left in the corpse after death.
And the annihilationist views noted in Digha Nikaya 1. Namely - that the self does not die when the body dies - suggest that post mortem survival is the norm.
This self, among others, as it is described is a WRONG view. It claims that this self, among others, does NOT exist after death. And yet it is a wrong view. It implies the destruction and extermination of an existent being, but is, according to the passage, not a CORRECT view. So, the correct view here is that this self DOES exist after death and will continue to inhabit the body until such time as it is released.4. Annihilationism (Ucchedavāda): Views 51–57
86. "To him another says: 'There is, good sir, such a self as you assert. That I do not deny. But it is not at that point that the self is completely annihilated. For there is, good sir, another self — divine, having material form, pertaining to the sense sphere, feeding on edible nutriment. That you neither know nor see, but I know it and see it. Since this self, good sir, is annihilated and destroyed with the breakup of the body and does not exist after death, at this point the self is completely annihilated.' In this way others proclaim the annihilation, destruction, and extermination of an existent being.
Personally, I have a nagging suspicion post mortem survival might be this way, but short of constantly rolling over in my grave when I die, if somebody could please help me put this idea to rest, i would greatly appreciate it.