So, We said, “Strike the slain man with part of it.” Thus does Allah bring the dead to life, and He shows you His signs that you might reason.
Many commentators believe that the priests of the Israelites took some of the sacrificed animal (from verses 2:67-71) and slapped it upon the dead man who then suddenly came to life and told everyone who really killed him. There is no prophetic statement that this happened, nor is there any proof that the man came alive, but this has been the favorite position of classical commentators, even though they have no corroboration in any Islamic or Jewish source documents. Muhammad Asad suggested in his commentary that this verse is really referring to the application of group investigation (apply some of it) to the situation (him or it) to resolve the murder. He also proves that when the grammar is deconstructed the old understanding is not tenable. I believe that verses 2:72-73 refer to the practice found in Deuteronomy 21:1-9, for by making a sacrifice and declaring that the culprit cannot be found (applying the principle of sacrifice-as-absolution to it, i.e., the situation), it makes blood feuds, false accusations and misguided revenge less likely, and thus saves lives from being unjustly taken, and God knows better. (Also see Leviticus 6: 1-13.) Whatever happened, it became the custom among the Israelites to make a sacrifice in cases of unresolved murder.
Emerick, Yahiya. The Meaning of the Holy Qur’an in Today’s English (p. 827). Unknown. Kindle Edition.