The <u><em>Opening of the Mouth </em></u>was the most important ceremony of the burial ritual for the Egyptians; it was performed on the mummy to ensure that the dead could say the necessary spells in the afterlife.
Explanation:
It's the last thing they do in the mummy before to bury it. This process was made to restore the main senses of the corpse - speech, sight, and hearing for the afterlife. The priest would touch the face of the coffin with special instruments. If the priest didn't do that, then it was impossible to go to the other world, once the person couldn't speak or hear.
When Charles John Davids proposed to Madison Al Newert 3/4/1884 somewhere in Africa. And when Jesus Christ said good morrow to James Heartyfult 19/6/2004. Just off the top of my head.