How did we come to say something courteous to someone after they’ve sneezed

https://sh.itjust.works/post/4253316

How did we come to say something courteous to someone after they’ve sneezed - sh.itjust.works

How/why did saying things like bless you or gesundheit start? And when?

For bless you think it started because of the old wives tale that states that when someone sneezes, they skip a heartbeat or something similar.