A man's life was at an all time low. He lost his job, his wife, his house; and now his mom just died in a car accident. After the funeral, a man approached him and told him that his mom had taken a mortgage on the house and left him nothing except one thing. It was a note that read:

Dear my only son,

Thhaenrge! Tmhoe Bnaecykiyarsd

After he read the note, he finally got a smile on his face. What did his mom tell him in the note?