Where in the Torah does it discuss sneezing & dying? Where did it originate?

I was going to send you the simple references but found this answer on the web written by Rabbi Moshe Bogomilsky:

“Behold, your father is sick.” (Gen. 48:1)

QUESTION:

1. The word “hinei” — “behold” — seems extra. The text should simply read avichah choleh — “your father is sick.”

2. Why is the word choleh written without a vav?

ANSWER: According to the Gemara (Bava Metzia 87a), up to this time no one was ever sick before dying. When the time would come to leave this world, a person would sneeze and die without any prior illness. Yaakov prayed to Hashem that this order be changed because it is proper that a person first become ill so that he will know he is about to die and he will be able to give his children and family a message before leaving the world.

Therefore, the messenger told Yosef “Hinei” — “Behold, it is a surprising thing” — avichah choleh — “your father is sick.”

The word choleh — “sick” — is written without a vav because it is the acronym for chutz lederech hateva (beyond the laws of nature). The messenger told Yosef, “What is happening to your father is not in accordance to the usual laws of nature.”

When someone sneezes, it is customary to say to him, “Tzu Gezunt,” indicating that the sneeze should be for healthy purposes and not, G-d forbid, the reverse.

Why do some people have a custom to pull their ear when they sneeze?

Death came to the world because Adam failed to listen to Hashem and sinned. Prior to Yaakov’s sickness, when the time would come for a person to leave the world, he would sneeze and his soul would depart.

Therefore, when a person sneezes, he pulls his ear as a reminder that he must “listen” to Hashem so that he will not be punished, G-d forbid, with the opposite of life.