How to say no?

When rejection is desperation to others, is it cruel to say no? It’s not that I do not want to help him. He’s like a brother to me. Yet, to ask me get a loan for him in order to repay his other loan is just too much. Although I wanted to help him very much, but my gut tells me that it’s going to be a very bad move, on my part, that is. Forgive me for being heartless, bro. You have to learn this lesson in a hard way.