The Holy Book 'Menorat Hamaor' (volume 2, chapter 5) writes the following fascinating but true story In the name of the Midrash Tanchuma.
There was a man who designated a place in his home to learn. Every day he would learn the tractate Chagiga which talks about the sacrifices to be brought in the holy temple during major Jewish holidays. He reviewed and reviewed this tractate his whole life; way beyond 30 years. Perhaps for even sixty years. He was fluent in that tractate though he was illiterate in all other tractates. When he died at home he did not have any family living with him; no one knew that he died. A woman entered his house and started crying, wailing and carrying on.
The neighbors heard the commotion, ran to the home and found this woman crying and carrying on. The woman told the neighbors that they should honor this deceased righteous man because he honored her and never abandoned or forgot about her even for a day. She begged the neighbors that they should bury him honorably as deserved and she guaranteed them they would merit Olam Haba, the World to Come.
All the women of the village gathered around this woman and they arranged for the righteous deceased man to be eulogized and buried honorably. At the burial, one of the village women, trying to understand the woman's carrying on and crying approached this woman and asked her 'who are you'? 'What is your name'?
She responded “my name is Chagigah. I am the personification of the tractate this man learned every day his whole life. I was sent here from heaven to tell the people of this town how special this man was, of this righteous man's diligence in learning. Even though I was the only tractate that he learned and he was ignorant in all other tractates he had such great respect and love for me.” After the funeral the woman disappeared.