what is the most precious word.....?

I have a dear friend. When she talks, she all says what she is thinking. When we are having a conversation, I was offended and annoy by strong words. So I told her that I didn’t like about her. I said that she might hurt someone with her straight talk. She seemed shocked very much because she had never heard abut her bad points from others and I’m sure she was hurt very much, too.
After I said all my thoughts, she gave me a gift. It is word of “thank you”. She thanks to me even though I said too much. So I was very surprised and touched by her word of thank you.
She wasn’t even angry, in fact she grateful to me. That day I learned a lot about myself and meaning of true friendship…