941. Abu Hurairah (May Allah be pleased with him) reported: I heard the Prophet (PBUH) saying, "Hurry up with the dead body (for its burial), for if it is pious, you are speeding it to goodness and if it is otherwise, you are laying an evil off your necks.''
[Al-Bukhari and Muslim].

Commentary:  This Hadith underlines the Prophet's command of an undelayed shrouding and burial of a dead body as well as the rationale behind it. Hence, there should be no unnecessary delay in the funeral, rather the burial procession should reach the grave with utmost haste without of course causing inconvenience to those following it, nor shaking the dead body.

942. Abu Sa`id Al-Khudri (May Allah be pleased with him) reported: The Prophet (PBUH) said, "When a dead body is placed on a bier and men carry it on their shoulders, if he was a pious man, it (corpse) says: `Take me in haste.' But if he was not righteous, it says to its bearers: `Woe to it. Where are you taking it?' Everything except man hears its voice. Had a human being heard its voice, he would have surely fallen into swoon.''
[Al-Bukhari].

Commentary:  Only Allah knows the reality as to how a dead body speaks. However, no improbability is involved in this matter. Allah is empowered to let any dead body speak if He so likes. We are supposed to believe it on the authority of authentic Ahadith.