promise ring finger

When I undergo a mission training 7 years ago my classmate and I decided to buy a silver ring with our name on it. It's kinda a promise ring. I put mine in my right ring finger. There are some people who had promise ring finger. They make a vow for something. Later on, when I have a daughter I want her to have a promise ring to keep herself until she get married. It would be beautiful promises to make to the Lord and for ownself.