Which kind-hearted person helped me, sent me a message when I met a strange mobile phone number and knew my name. If I ask him, I won't say anything, but I will know when I meet him.

You can't trust this stranger. In modern society, it is not difficult to get a stranger's mobile phone number. All I know is that your name means nothing. I don't know what will happen if you meet him for this. Maybe you can ask him some questions that only your friends know, and verify whether he is your friend or not. If he can't answer, or on the grounds of "don't tell, we'll know when we meet", then you don't need to meet this stranger. After all, do you want your safety or satisfy your curiosity? Even if this person is really your good friend, you don't have to feel sorry for him, because his behavior is wrong. As your friend, he should understand your sense of self-protection. If he can't understand, you should consider whether this person is worthy of being your friend, because he only thinks about himself in the whole thing.