Now my main aim of creating this thread is that a friend asked me to send my BTC wallet address so that he can send me Bitcoin for me to sell it and send him fiat, but I am curious because of my safety since I don't know the source of his BTC if he got it by scamming someone. A thought cam to me that this might be a risky transaction and I don't want to send him my exchange wallet address.
Has your friend giving you any reason for you to suspect that he is a criminal or a scammer in recent times? Because for you to generate such thoughts on his request for your btc wallet address to help him receive some BTC it means you two have had history that connects him to some scams. Anyway, I get your message clear and it's a point worth taking into consideration.
Well, have you heard of mixers? Not sure you do. Maybe it's time you do a research about it. It will help you get answers to what you looking for.