Is it permissible to sit and speak with the deceased when visiting their grave?

It is established that the Prophet, peace and blessings be upon him, addressed the slain polytheists at Badr, saying: "They can hear what I am saying." He also commanded us to greet the people of the graves and supplicate for them. However, it was not part of his guidance, nor that of his Companions, to sit by a grave and address the deceased with anything other than the prescribed greetings and supplications. Going beyond that may fall into innovation in religion (bid'ah), extremism (ghuluw), or wailing (niyāḥah). The Prophet, peace and blessings be upon him, said: "Whoever introduces into this matter of ours that which is not from it will have it rejected."